The Ontario Building Code | Corbelling for Cavity Walls
9.20.12.2. Corbelling for Cavity walls
(1) Cavity walls of greater thickness than the foundation wall on which they rest shall not be corbelled but may project 25 mm over the outer face of the foundationwall disregarding parging.
(2) Where the foundation wall referred to in Sentence (1) is unit masonry, it is permitted to be corbelled to meet flush with the inner face of a cavity wall provided,
(a) the projection of each course does not exceed half the height or one-third the width of the corbelled unit, and
(b) the total corbel does not exceed one-third of the foundation wall thickness.
In Plain Language
Corbelling for cavity walls has specific requirements set out in this article, addressing this technique's use in the two-wythe cavity wall system.
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.