The Ontario Building Code | Protection of Soffits
220.127.116.11. Protection of Soffits
(1) This Article applies to the portion of any soffit enclosing a projection that is,
(2) Except as provided in Sentences (4) and (5), the soffit described in Sentence (1) shall be protected in accordance with Sentence (3) where the soffit encloses,
(3) Protection required by Sentence (2) shall be provided by,
(a) noncombustiblematerial having a minimum thickness of 0.38 mm and a melting point not below 650°C,
(c) not less than 11 mm thick plywood,
(d) not less than 12.5 mm thick OSB or waferboard, or
(e) not less than 11 mm thick lumber.
(4) In the case of a soffit described in Sentence (1) that is at the edge of an attic or roof space, and completely separated from the remainder of the attic or roof space by fire blocks, the requirements in Sentence (2) do not apply.
(5) Where all suites spanned by a common attic or roof space or situated above or below the projecting floor are sprinklered, the requirements in Sentence (2) do not apply provided that all rooms, including closets and bathrooms, having openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings in the wall beneath the soffit are sprinklered, notwithstanding any exceptions in the sprinkler standards referenced in Article 18.104.22.168.
9.10.13. doors, Dampers and Other Closures in Fire Separations