The Ontario Building Code | Fire-Rated Walls
9.24.3.2. Fire-Rated walls
(1) Steel studs used in walls required to have a fire-resistance rating shall be installed so that there is not less than a 12 mm clearance between the top of the stud and the top of the runner to allow for expansion in the event of fire.
(2) Except as provided in Article 9.24.3.6., studs in walls referred to in Sentence (1) shall not be attached to the runners in a manner that will prevent such expansion.
(3) Framing above doors with steel door frames in non-loadbearingfire separations required to have a fire-resistance rating shall consist of two runners on the flat fastened back to back.
(4) The lower runner required in Sentence (3) shall be cut through the flanges and be bent at each end to extend upwards at least 150 mm and fastened to the adjacent studs.
In Plain Language
Fire-rated walls built with steel stud framing must meet the specific requirements set out in this article, ensuring the assembly achieves its required fire-resistance rating.
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.