Crawl Spaces as Warm Air Plenums,

(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.

Article Ontario Regulation 332/12 Building Code,   Information published by for educational purposes only.