Div. B › Part 9 › 9.18 › 9.18.7 — Fire Protection

9.18.7.1 — Crawl Spaces as Warm Air Plenums

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(1) Only crawl spaces under 1-storey portions of dwelling units shall be used as warm air plenums.

(2) Enclosing material in crawl spaces described in Sentence (1), including insulation, shall have a surface flame-spread rating not greater than 150.

(3) Combustible ground cover used as enclosing material in Sentence (2) shall be covered with noncombustible material.

(4) Noncombustible material described in Sentence (3) shall,

(a) extend not less than 300 mm beyond the projection of a register opening, and

(b) have turned-up edges.

OBC Definitions

Defined terms on this page

combustible

means that a material fails to meet the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials”.

dwelling unit

means a suite operated as a housekeeping unit, used or intended to be used by one or more persons and usually containing cooking, eating, living, sleeping and sanitary facilities.

flame-spread rating

means an index or classification indicating the extent of the spread of flame on the surface of a material or an assembly of materials, as determined in a standard fire test prescribed in this Code.

noncombustible

means that a material meets the acceptance criteria of CAN/ULC-S114, “Test for Determination of Non-Combustibility in Building Materials”.

plenum

means a chamber forming part of an air duct system.

storey

means , except for the purposes of Part 7 of Division B, the portion of a building, (a)that is situated between the top of any floor and the top of the floor next above it, or (b)that is situated between the top of the floor and the ceiling above the floor, if there is no floor above it.

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