Technical Booklet E Fire Safety·Page 125·4.48 Note 1
Enclosure requirements for pipes and ducts
Enclosures for drainage, water supply, or vent pipes within compartment walls or floors must be bounded by compartment elements, have Class 0 or European Class B-s3,d2 internal surfaces, and must not include access panels opening into circulation spaces or bedrooms.
The enclosure should –
(a) be bounded by a compartment wall or floor, an outside wall, an intermediate floor or a casing;
(b) have internal surfaces (except framing members) of Class 0 (National class) or Class B-s3,d2 or higher (European class);
(c) not have an access panel which opens into a circulation space or a bedroom; and
(d) be used only for drainage, water supply or vent pipes for a drainage system.
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