1 Scope
This British Standard specifies requirements for two classes of wall ventilating units
as follows:
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class 1: airbricks for use in external walls;
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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.
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a) 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.
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b) 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.