The Ontario Building Code | Metal Roof Deck Assemblies
18.104.22.168. Metal Roof Deck Assemblies
(1) Except as permitted by Sentence (2), a metal roof deck assembly shall meet the conditions of acceptance of CAN/ulc-S126, "Test for Fire Spread Under Roof-Deck Assemblies", if,
(a) it supports a combustible material above the deck that could propagate a fire beneath the roof deck assembly, and
(b) the deck is used to comply with the requirements of Sentences 22.214.171.124.(2), 126.96.36.199.(2), 188.8.131.52.(2), 184.108.40.206.(2), 220.127.116.11.(2) and 18.104.22.168.(2) for noncombustible construction.
(2) The requirements of Sentence (1) are waived provided,
(a) the combustiblematerial above the roof deck is protected,
(ii) by a thermal barrier conforming to one of Clauses 22.214.171.124.(2)(c) to (e) that is located on the underside of the combustible material or beneath the roof deck,
(b) the buildingis sprinklered, or
(c) the roof assembly has a fire-resistance rating not less than 45 min.
3.1.15. Roof Covering