The Ontario Building Code | Flame-Spread Rating
9.10.3.2. Flame-Spread Rating
(1) Where a flame-spread rating is required in this Section for an element of a building, such rating shall be determined in accordance with the test methods described in Part 3, or in accordance with MMAH Supplementary Standard SB-2, "Fire Performance Ratings".
(2) Unless the flame-spread rating is referred to in this Part as a "surface flame-spread rating", it shall apply to any surface of the element being considered that would be exposed by cutting through it as well as to the exposed surface of the element.
In Plain Language
Interior finish materials must meet flame-spread rating limits set out in this article, controlling how quickly fire could spread across a surface like a wall or ceiling.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.