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Home > Building elements and structures > Masonry, walls and chimneys

Masonry, walls and chimneys


AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel ¿ flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls ¿ repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or ¿ in extreme cases ¿ collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress¿strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH ¿ a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/2 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468/1 

AAC 'aircrete' blocks and masonry
This Digest covers the main technical issues and answers the frequently asked questions on specification, application and performance of AAC masonry in the light of current regulations and guidance. It evaluates the green credentials on the basis of data on energy and resource usage published by the manufacturing industry. This Digest is in two parts; figure, table and reference numbering continues into Part 2 which contains the full list of references, documents mentioned in the text, and further reading. DG468 

Aircrete tongue and grooved block masonry
For the construction of housing and small commercial buildings, solid aircrete blockwork with an outer finish that protects against penetration of rain, wind, pests and grime offers an attractive alternative to the complexities of cavity walls. The productivity advantages of aircrete blockwork used with thin bed mortar technology and mortar-less interlocking vertical (perpend) joints, when combined with the simplicity of solid wall construction, offers a rapid, economical building system which is less demanding in terms of masons' skills but which can still meet all the requirements of the Building Regulations. This Information Paper sets out the background research on the key aspects of performance and gives an introductory guide on constructional best practice using this wall system. IP7/05 

Aircrete: thin joint mortar systems
Thin mortar joint systems are being introduced to the UK for commercial or industrial buildings. Using aircrete units with a rapid setting mortar, the thin joint system allows rapid masonry construction without adversely affecting quality. Some aspects of thin joint construction differ from traditional masonry construction and they must be understood in order to gain the maximum benefits from the system. This Digest explains the technical background, properties and benefits of thin joint mortar systems. DG432 

Assessing the performance of timber frame wall panels subject to racking loads
It is necessary to assess the performance of wall panels by testing, and this paper proposes a method of test suitable for this purpose. IP12/84 

Assessment of hard body impact resistance of external walls
Summarises the research which has led to the development of an assessment method for estimating the resistance of wall claddings to impacts from hard objects, and the background to proposals for appropriate levels of impact resistance for particular cladding uses. IP19/81 

Building brickwork or blockwork retaining walls
This guide is for builders, designers and planners. It deals with types of retaining walls, soil classification, walls in sloping ground, materials, foundations, construction and, most importantly, safety. NHBC accepts design solutions based on this Good Building Guide. GG27 

Building damp-free cavity walls
Cavity walls should be built so that the inner leaf stays dry. Many building details are designed with this express purpose and are long-established. However, dampness is still a common problem in modern buildings, due to faulty design or construction of damp-proofing measures or to wrong choice of material. This Guide shows how to make sure new cavity walls do not suffer from dampness problems. GG33 

Building reinforced, diaphragm and wide plan freestanding walls
This guide gives guidance for stable construction of freestanding walls built with a range of common brick or blockwork wall types. GG19 

Building simple plan brick or blockwork freestanding walls
A rule-of-thumb guide for contractors and site supervisors showing how to build sound freestanding boundary walls. GG14 

Cleaning exterior masonry
This digest is relevant to all types of buildings, including private, public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method.  DG449 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 1 outlines the approach that should be taken to managing cleaning projects; types of cleaning; choosing cleaning methods; specification and tendering criteria; research and trial cleaning; and analyses the cleaning of a building as a process.  DG449/1 

Cleaning exterior masonry
Cleaning the exterior masonry of buildings presents issues for owners, their advisors and contractors. This Digest describes these issues, often presented as risks because of the materials and methods used, and the conditions encountered. It is especially relevant to public and historic buildings. Part 2 categorises a range of widely used cleaning methods, highlights key issues, and describes the problems and risks associated with each method. DG449/2 

Cleaning external walls of buildings
Cleaning building façades can enhance appearance, but may also make the building more unsightly and damage the walling materials. Trials can help determine appropriate methods, risks involved and if cleaning is warranted. Part 1 of this Good Repair Guide outlines actions to take before cleaning and describes the methods available. Part 2 gives advice on the methods and precautions for different types of soiling on different wall surfaces to help surveyors and contractors. GR27 

Corrosion of metal components in walls
This Digest reviews the history and incidence of problems with metal components in walls, particularly wall ties. It considers problems of corrosion, inadequate provision or poor specification and what action can be taken, particularly where structural stability is threatened. Reinstatment is often feasible and may cost a fraction of the whole rebuilding cost, so methods are suggested. With IP13/90, Digests 329 and 401, and Good Building Guide 29, this Digest offers a package of information on problems and remedial installation of wall ties, straps and fixings into existing walls.  DG461 

Corrosion of steel wall ties: history of occurrence, background and treatment
This paper describes the history and epidemiology of wall tie corrosion and some methods for remedial action. Reinstatement of walls is often feasible and at much less cost compared with rebuilding. IP12/90 

Corrosion of steel wall ties: recognition and inspection
This paper describes how to recognise and assess wall tie corrosion in the field. It also includes inspection methods. IP13/90 

Design of masonry walls subjected to concentrated vertical loads
Current codes of practice for the design of such walls are inaccurate. This paper deals with the main parameters that affect local bearing stresses and gives design guidance. IP10/92 

Domestic chimneys for solid fuel – flue design and installation
This Good Building Guide gives advice on design and construction of chimneys and flues to vent combustion gases safely to the outside air and induce a good air flow to suit the appliance and its heat output.  GG46 

Dynamic stiffness of wall ties used in masonry cavity walls: measurement procedure
The sound insulation of masonry cavity walls is partly determined by the number and dynamic stiffness of the wall ties used. Wall ties have a drip to prevent water passing from the outer to the inner leaf which means that their dynamic stiffness cannot be calculated from their dimensions and properties. The stiffness also depends on the width of the cavity. The dynamic stiffness of wall ties therefore needs to be measured experimentally: this paper describes such a measurement procedure. IP3/01 

Earth, clay and chalk walls
Around the UK, a variety of earth-walling construction methods and practices have been developed over many centuries depending on the characteristics of the subsoils and on local traditions. Since the 1980s there has been a resurgence of interest in the techniques used mainly to ensure appropriate repairs for maintenance and extension of existing buildings. There is also a growing interest in earth-walling construction methods and practices for new build as a means of reducing the environmental impact of building and of employing more sustainable and natural building methods. This Good Repair Guide focuses on inspection of existing earth, clay and chalk walls and the use of traditional repair methods to rectify defects. GR35 

Field measurements of the effect of plastered lightweight masonry inner leaves on the sound insulation of plastered brick and dense blockwork party walls
Results for plastered brick and dense blockwork party walls associated with plastered lightweight masonry inner leaves of external walls are here compared with earlier results from similar party walls associated with heavier masonry or lightweight panelling external wall leaves to find whether sound insulation is reduced. IP24/82 

Freestanding brick walls – repairs to copings and cappings
Gives recommendations for repair of deteriorated copings or cappings on existing walls, and for replacement of copings or cappings where a wall is being lowered in height to reduce risk of collapse. GG17 

Installing wall ties
Lack of skill or care in installing wall ties can lead to distortion, cracking, or – in extreme cases – collapse. The outer leaf is also the rain shield for the building. Badly installed ties can lead to rain penetration and dampness in the inner leaf. This Good Building Guide gives practical advice on installing wall ties in new buildings. GG41 

Installing wall ties in existing construction
Describes the range of techniques available for reinstatement of cavity walls by inserting new wall ties. DG329 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction.  GG44 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/2 

Insulating masonry cavity walls
With increasing pressure to provide ever thicker levels of insulation there is concern that thermally upgrading conventional cavity walls, consisting of two leaves of masonry, may prove impracticable. Part 1 of this Good Building Guide highlights techniques and materials for insulating cavity walls. Part 2 provides guidance on how to reduce the associated technical risks. The guidance is for cavity walls having two masonry leaves; it is not suitable for timber-framed construction. GG44/1 

Insulating solid masonry walls
Solid masonry is used in about 15% of existing houses, many of which could be thermally upgraded. Increased insulation demanded by building regulations may present technical challenges to cavity and framed construction and it may be appropriate to specify solid masonry construction for new build. This Good Building Guide highlights risks associated with solid masonry walling and provides solutions for improving its thermal performance. GG50 

Masonry and concrete structures: measuring in-situ stress and elasticity using flat jacks
This Digest describes how compressive stress in members and local stress–strain behaviour can be measured with a flat jack (a flat, flexible envelope filled with hydraulic fluid which can be pressurised with a pump and works on the lever principle). DG409 

Masonry, walls and chimneys pack
A valuable reference library of BRE Digests, Good Building Guides, Good Repair Guides and Information papers on masonry, walls and chimneys. One of a series of 19 compilations of BRE expert guidance and advice and presented in an attractive ring binder for ease of use. Exceptional value. Features / Benefits Exceptional value 43 BRE publications compiled into a single binder Forms an easy to use library of key information and guidance Readership Construction professionals  AP261 

Measuring the compressive strength of masonry materials: the screw pull-out test
The compressive strength of masonry materials can be assessed by a test developed by BRE. It can be used on mortar and some masonry units with strengths up to 7 N/mm2. This Digest explains the screw pull-out test, its technical background, calibration and the interpretation of results. DG421 

Performance specification for wall ties
The overall performance requirements for ties for masonry cavity walls and masonry cladding are discussed in the context of the current and future design environment. IP4/84 

Providing temporary support during work on openings in external walls
Shows how to provide temporary support when replacing lintels or changing the size of window or door openings. Gives guidance on choice of materials and typical methods for supporting walls, floors and roofs. GG15 

Rain penetration of cavity walls: report of a survey of properties in England and Wales
During the winter of 1983/84, the number of reports of rain penetration of insulated cavity walls seemed unusually high. A survey carried out by BRE, collaborating with BBA, BEC and NHBC, confirmed an increase, concentrated in places where exceptional weather had been recorded. In nearly every case there was also a construction or design fault. IP2/88 

Rammed earth: design and construction guidelines
Rammed earth walling is a beautiful, durable building material with a long and successful tradition in the UK and around the world. For modern construction it offers a high-quality and sustainable building method suitable for a range of external and internal applications. Often using local materials, rammed earth buildings have characteristic textures and colours, with structural and thermal properties suited to a range of situations. Until now there has been no authoritative guidance on the use of rammed earth in the UK. This book presents state-of-the-art practical guidance on material selection, construction, structural design, architectural detailing, maintenance and repair of rammed earth. It contains numerous photos of rammed earth buildings in the UK, Europe, the USA, Africa and Australia, and includes construction details. The aim of the book is to inform, develop and encourage the use of rammed earth wall construction for housing and other low- and medium-rise buildings. The guidance has been derived from extensive testing and research at the University of Bath, funded by the DTI Partners in Innovation programme. EP62 

Reinforced autoclaved aerated concrete panels
Reinforced autoclaved aerated concrete (RAAC) panels are widely used in mainland Europe but serviceability problems have occurred in the UK with some panels designed and built before 1980. This paper describes: concerns about the performance of RAAC roof panels designed before 1980, laboratory testing of RAAC roof panels after 20 years' service, and newly fabricated panels, mechanisms influencing in-service behaviour, design guidance in prEN 12602, and testing RAAC panels fabricated to the new guidance. BR445 

Removing internal loadbearing walls in older dwellings
In older properties an open-plan ground floor is often created by removing part of an internal loadbearing wall. This guide is for those responsible for specifying, carrying out and inspecting such alterations. GG20 

Repairing brick and block freestanding walls
If freestanding walls are not well built, they can fail early in their life. And if local conditions change a well established, soundly built wall can be damaged or even collapse. Before starting on any repair, whether a minor patching up or a major rebuilding, it is important to find out what caused the problem. This Guide aims to help in assessing damage in freestanding masonry walls, establishing the cause, and carrying out effective repairs.  GR28 

Repairing brick and block masonry
This Digest lists causes of damage, through accident or neglect, to small, generally domestic, masonry buildings and summarises methods of repair. It indicates certain avoidable risks and suggests special precautions to be taken in the course of repair work to prevent recurrence. DG359 

Repairing chimneys and parapets
Chimneys and parapets are more exposed to the elements than any other part of a building. If they are allowed to get into a bad state of repair, rain can penetrate to the inside of the building. Falls of masonry from unstable chimneys and parapets pose real danger to people below. It is vital that repairs are carried out to a high standard and that bricks and mortar, and concrete and metal components, are carefully selected to ensure they are durable in severe exposure. This Guide deals with how to make damaged chimneys and parapets safe and weathertight. GR15 

Repairing damage to brick and block walls
Brick and block masonry suffers damage from a variety of causes, not all of which require immediate or extensive attention. This Guide helps anyone carrying out these repairs to choose the appropriate method for any given situation. It emphasises the importance of assessing the structural stability of damaged walls. GR3 

Replacement of cavity wall ties using resin-grouted stainless steel rods
In the maintenance of buildings there is sometimes a need for a method for tying the two leaves of an existing cavity wall without resorting to demolition and reconstruction of the non-loadbearing leaf. This paper describes the method using resin-grouted stainless steel rods. IP29/79 

Replacing masonry wall ties
Distress of cavity walls is sometimes attributable to corrosion or absence of metal ties. Generally the wall bulges, cracks or leaks, but if subjected to high wind loads it might even collapse. This Guide shows how to assess masonry wall ties and, when appropriate, how to replace them. GR4 

Replacing wall ties
This Digest discusses site workmanship and quality assurance for the installation of replacement wall ties in masonry walls. DG401 

Repointing external brickwork walls
This Good Repair Guide provides advice for builders and householders on choosing the right mortar mix and how to repoint. GR24 

Retro-installation of bed joint reinforcement in masonry
Installing bed joint reinforcement into existing walls, 'retro-reinforcement', enables repair of cracks, sagging lintels and flat arches, developing arches or cantilevers within a wall to span over subsidence, increasing the flexural strength and shear resistance of walls to combat wind and seismic loading, and reconnecting cracked or parted buttresses. This guide tabulates the cross-sectional area and tensile strength of typical bars, and grout properties. Performance for steel and epoxy-glass fibre reinforcements are given. Where subsidence of foundations causes cracking of masonry, remedial reinforcement, combined with new piles, can be cheaper and less invasive than massive underpinning works. Illustrations show typical problems and solutions. GG62 

Summer condensation on vapour checks: tests with battened, internally-insulated walls
Some of the factors controlling condensation on the back of vapour checks during a summer were compared in an experimental building. The number of days that condensation was present depended on orientation, materials and conditions. Remedies were tested with varying degrees of success. IP12/88 

Supporting temporary openings
Forming a new opening in a loadbearing wall or enlarging an existing opening are both common operations for builders involved in alteration work. But it can be difficult to decide how much temporary support is needed while the work is done, and to make sure it is properly installed and safe. This Good Repair Guide gives advice on how to provide safe support when creating or enlarging openings or replacing lintels in traditional buildings. GR25 

Surveying brick or blockwork freestanding walls
Shows what to look for when assessing masonry boundary walls that may need to be repaired or rebuilt. GG13 

Surveying masonry chimneys for repair or rebuilding
During the life of a building, chimneys may need repair, be required to act as flues for different fuels or appliances, or become redundant. This Guide shows what to look for when assessing chimneys for repair, re-use or decommissioning. GG2 

Surveying the moisture contents of cavity-filled timber-framed dwellings
Describes a method of surveying the moisture contents of timber in those timber-framed dwellings which have had the cavity between their cladding and the sheathing thermally insulated after occupation. It gives guidance on moisture levels likely to be acceptable for the timber frame and suggests remedial action should high moisture levels be found. IP1/85 

Temporary support for openings in external walls: assessing load
Many buildings will require minor structural alteration or repair around openings; others will need new or enlarged openings. This Guide gives a simple procedure for assessing loads above lintels in traditionally built brick or brick and block housing. GG10 

Testing bond strength of masonry
Covers the technical background, calibration and interpretation of results for bond wrenches and features the use of the BRENCH – a powerful in-situ tool used for investigating suspect masonry, for quality control of new work and for laboratory investigation of bond. DG360 

The performance of cavity wall ties
Based on the laboratory measurements of the thickness of zinc on some 150 wall ties removed from 80 buildings owned by the Property Services Agency and local authorities, typical lives are deduced for galvanised wall ties conforming to the minimum standards of BS 1243:1978. It is concluded that more durable ties are required for new construction but that the majority of existing buildings are sufficiently robust for wide-spread problems to be unlikely. IP4/81 

The spacing of wall ties in cavity walls
A review of the results of loading tests on masonry walls with cavities exceeding 75 mm. IP6/86 

Thin layer mortar masonry
Thin layer mortar technology, which is rapidly gaining in popularity among UK builders, overcomes many of the actual and perceived disadvantages of conventional masonry techniques. Thin layer mortar is easy to mix on site. The laying technique is simple and fast using large accurately sized block units and less mortar. The result is increased productivity and savings in labour and materials.Thin layer mortar technology complying with building regulations and codes of practice, aims to retain masonry as a preferred option for house construction because of its proven durability, inherent fire resistance, good noise exclusion and low maintenance. GG58 

Ties for cavity walls: new developments
The durability of galvanised mild-steel ties made before 1981 has been shown to be insufficient. This is a review of the history of the development of wall ties, and of recent improvements in materials specifications and performance; also of newer forms of tie which are described and illustrated. IP16/88 

Ties for masonry cladding
Fixing systems appropriate to some of the common cladding situations are reviewed, together with the more recent improvements in both materials specifications and performance. Describes and illustrates forms of tie which are suitable for fixing new masonry to timber, concrete, steel and lightweight concrete slabs or blockwork. Remedial ties are also described. IP17/88 

Ties for masonry walls: a decade of development
The development and evolution of wall ties were reviewed in BRE Information Papers 16/88 and 17/88. This Paper covers the further development over the last decade and anticipates the European standard, EN 845-1. IP11/00 

Untied cavity party walls: structural performance when using AAC blockwork
Unwanted noise is the most frequent cause of complaint by occupiers of dwellings with party walls. Therefore the concept of a cavity party (separating) wall, built with loadbearing masonry but without wall ties, has generated wide interest. This paper describes a series of element tests, followed by a full-scale model test, that show that an untied cavity party wall can be a stable structure and achieve satisfactory sound attenuation. It will interest manufacturers and suppliers of AAC blocks, building designers and specifiers. IP1/99 

Urea-formaldehyde foam cavity wall insulation: reducing formaldehyde vapour in dwellings
Suggests what the householder, installer or builder can do to reduce the concentration of vapour. IP7/84 

Vapour diffusion through timber-framed walls
This paper is concerned with preventing moisture accumulation from water vapour diffusion inside the building. IP1/81 

Walls, windows and doors
This third book in the BRE Building Elements series considers the main vertical elements of buildings, both external (including walls, windows and doors) and internal (including separating walls, partitions and internal doors). It deals in outline with the performance requirements of the spaces from which the required performances of the walls are derived, and also, in principle, with the achieved performances and deficiencies of the fabric over the whole age range of the national building stock. This book is addressed primarily to building surveyors and other professionals performing similar functions, such as architects and builders, who maintain, repair, extend and renew the national building stock. It will also find application in the education field, where lecturers can find indication of where the construction syllabus needs attention. Statistics are given of BRE Advisory Service investigations of walls by type of defect and by type of building. BR352