The Ontario Building Code | Bracing and Lateral Support
9.23.10.2. Bracing and Lateral support
(1) Except as provided in Sentence (2), each exterior wall in each storeyshall be braced with at least one diagonal brace conforming to Sentence (3).
(2) Bracing is not required where the walls,
(a) have an interior finish conforming to the requirements of Section 9.29., or
(b) where the walls are,
(i) clad with panel-type siding,
(ii) diagonally sheathed with lumber, or
(iii) sheathed with plywood, OSB, waferboard, gypsum or fibreboard sheathing.
(3) Where bracing is required, it shall,
(a) consist of not less than 19 mm by 89 mm wood members,
(b) be applied to the studs at an angle of approximately 45° to the horizontal, and
(c) extend the full height of the wall on each storey.
(4) Bracing described in Sentence (3) shall be nailed to each stud and wall plate by at least two 63 mm nails.
(5) Whereloadbearing interior walls are not finished in accordance with Sentence (2), blocking or strapping shall be fastened to the studs at mid-height to prevent sideways buckling.
In Plain Language
Walls need bracing and lateral support as set out in this article, preventing the wall from racking or buckling under wind or other lateral loads.
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.