Hull Construction Regulations (C.R.C., c. 1431)

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.

234. (1) Where a ventilation duct greater than 0.075 m² in cross-section passes through an ‘A’ Class division, the duct shall be fitted with a fire damper that is

• (a) of the fail-safe automatic closing type;

• (b) capable of being closed manually from both sides of the division; and

• (c) fitted with an indicator that shows whether the damper is open or closed.

(2) Where a ventilation duct passes through a space that is enclosed by ‘A’ Class divisions but does not serve that space and the duct does not have a fire rating at least equal to that of the division that it pierces, the duct shall be fitted at each point at which the duct pierces a division with a fire damper described in subsection (1).

235. (1) Subject to subsection (2), no duct provided for the ventilation of a machinery space of Category ‘A’, galley or car deck space shall pass through an accommodation space, service space or control station unless the duct is

• (a) constructed of steel that,

  • (i) in the case of a duct that has a diameter or width of 300 mm or less, has a thickness of at least 3 mm,

  • (ii) in the case of a duct that has a diameter or width greater than 760 mm, has a thickness of at least 5 mm, or

  • (iii) in the case of a duct that has a diameter or width greater than 300 mm but not greater than 760 mm, has a thickness determined by interpolation;

• (b) suitably supported and stiffened; and

• (c) insulated to an ‘A-60’ Class fire rating throughout the accommodation space, service space or control station.

(2) A duct provided for the ventilation of a machinery space of Category A, galley or car deck space may pass through an accommodation space, service space or control station if the duct is

• (a) constructed of steel;

• (b) fitted close to every boundary penetrated with a fire damper that is

  • (i) of the fail-safe automatic closing type, and

  • (ii) capable of being manually operated from either side of the division; and

• (c) insulated to an ‘A-60’ Class fire rating from the machinery space, galley or car deck space to a point at least 5 m beyond each fire damper.