Hull Construction Regulations

233 (1) Subject to subsection (2), ventilation ducts shall be made of non-combustible materials.

(2) A ventilation duct may be made of restricted-fire-risk combustible materials in accordance with TP 439, Structural Fire Protection Standards: Testing and Approval Procedures, as amended from time to time, if the duct

• (a) does not exceed 2 m in length and 200 cm² in cross-section;

• (b) is not located closer than 600 mm from any penetration of an ‘A’ Class division, ‘B’ Class division or ‘A’ or ‘B’ Class ceiling, measured from the point of the duct that is closest to such penetration; and

• (c) is used only at the terminal end of the ventilation system of which it is a part.