The Ontario Building Code | Thickness
9.20.4.1. Thickness
(1) Except as provided in Sentence (2), mortar joint thickness for burned clay brick and concrete masonry units shall be 10 mm.
(2) Permitted tolerances in head and bed joints shall be -5 mm to +10 mm.
In Plain Language
Masonry walls must meet minimum thickness requirements set out in this article, ensuring adequate structural capacity for their height and loading.
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.