Combustible Components for Exterior Walls
(1) Except as provided in Sentences (2) and (4), combustible components are permitted to be used for an exterior non-loadbearing wall assembly in a building required to be of noncombustible construction, provided that,
(a) the building is,
(i) not more than 3 storeys in building height, or
(ii) not more than 6 storeys in building height if sprinklered,
(b) when tested in accordance with CAN/ULC-S134, “Fire Test of Exterior Wall Assemblies”, the wall assembly satisfies the following criteria for testing and conditions of acceptance:
(i) flaming on or in the wall assembly does not spread more than 5 m above the opening, and
(ii) the heat flux during the flame exposure on the wall assembly is not more than 35 kW/m2 measured at 3.5 m above the opening, and
(c) the interior surfaces of the wall assembly are protected by a thermal barrier conforming to Sentence 3.1.5.12.(5).
(2) Except as permitted by Articles 3.2.3.10. and 3.2.3.11., where the limiting distance in Tables 3.2.3.1.B. to 3.2.3.1.E. permits an area of unprotected openings of not more than 10% of the exposing building face, the construction requirements of Table 3.2.3.7. shall be met.
(3) A wall assembly permitted by Sentence (1) that includes combustible cladding of fire-retardant treated wood shall be tested for fire exposure after the cladding has been subjected to an accelerated weathering test as specified in ASTM D2898, “Accelerated Weathering of Fire-Retardant-Treated Wood for Fire Testing”.
(4) The requirements of this Article do not apply where foamed plastic insulation is used in an exterior wall assembly of a building and the insulation is protected in conformance with Sentences 3.2.3.8.(1) and (2).
Article 3.1.5.5 Ontario Regulation 332/12 Building Code, Information published by oncodes.ca for educational purposes only.
