Committees responsible for this British Standard

The preparation of this British Standard was entrusted to Technical Committee B/519, Masonry and associated testing, upon which the following bodies were represented:

Autoclaved Aerated Concrete Products Association

Brick Development Association

British Ceramic Research Ltd.

British Precast Concrete Federation Ltd.

Building Employers’ Confederation

Concrete Block Association

Department of the Environment (Building Research Establishment)

District Surveyors’ Association

Local Authority Organizations

Mortar Producers’ Association Limited

National House-building Council

Royal Institute of British Architects

Stone Federation

The following bodies were also represented in the drafting of the standard, through subcommittees and panels:

British Civil Engineering Test Equipment Manufacturers’ Association

Calcium Silicate Brick Association Limited

Consumer Policy Committee of BSI

Federation of Civil Engineering Contractors

This British Standard, having been prepared under the direction of the Sector Board for Building and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 15 April 1995

First published June 1933

First revision March 1945

Second revision February 1967

First published as BS 493‑2 December 1970

Number changed to BS 493 by amendment in November 1980

Second edition April 1995

The following BSI references relate to the work on this standard:

Committee reference B/519

Draft for comment 93/105570 DC, DC 10/30155844

Foreword

BS 493:1995+A1:2010 supersedes BS 493:1995, which is withdrawn.

The start and finish of text introduced or altered by Amendment No. 1 is indicated in the text by tags . Minor editorial changes are not tagged.

Amendment No. 1 has updated all references in Clause 4 and the Normative references.

The present standard is in accordance with the requirements and recommendations for the co-ordination of dimensions in building given in BS 6750 and BS 6954‑1 to BS 6954‑3 respectively.

Some typical examples of airbricks are illustrated, but it is not possible to include the wide range of patterns which can conform to this standard.

Product certification. Users of the British Standard are advised to consider the desirability of third party certification of product conformity with this British Standard based on testing and continuing product surveillance which may be coupled with assessment of a supplier’s quality systems against the appropriate Part of BS 5750.

Enquiries as to the availability of third party certification schemes are forwarded by BSI to the Association of British Certification Bodies. If a third party certification scheme does not already exist, users should consider approaching an appropriate body from the list of Association members.

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

1 Scope

This British Standard specifies requirements for two classes of wall ventilating units as follows:

class 1: airbricks for use in external walls;
class 2: wall ventilators or gratings for internal use.

Some typical examples of designs are shown in Figure 1, Figure 2 and Figure 3. Other patterns may however be supplied, provided they conform to the requirements of this standard.

Guidance on the information to be supplied by the purchaser when ordering is given in Annex A. This standard contains no requirements for the following properties.

Durability (other than resistance to colour change of thermoplastics materials). It is recommended that where there is uncertainty about durability then expert advice should be sought.

Fire properties of thermoplastics materials. The general use of thermoplastics airbricks, wall ventilators and gratings in isolation in masonry is considered to have an insignificant effect on the spread of fire. However, special consideration should be given to the use of thermoplastics air bricks where it is intended to group a number of them together, e.g. for boiler house ventilation.
Compressive strength of thermoplastics air bricks. The general use of these in isolation is considered to have to have an insignificant effect on masonry strength. However, special consideration should be given to their use where it is intended to group a number of them together,e.g. for boiler house ventilation.

2 References

2.1 Normative references

2.2 Informative references

3 Definitions

4 Materials

5 Manufacturer’s certificate

6 Marking

6.1

6.2

7 Airbricks for external use (class 1 units)

7.1 Materials and design

7.2 Workmanship

7.3 Dimensions

7.4 Apertures

7.5 Wall hold

8 Wall ventilators or gratings for internal use (class 2 units)

8.1 Materials and design

8.2 Workmanship

8.3 Additives

8.4 Dimensions

8.5 Apertures

8.6 Width of web surround

8.7 Screening

8.8 Testing of plaster units

BS 493:1995+A1:2010

Specification for airbricks and gratings for wall ventilation

Current

Published:

15 Apr 1995