The Ontario Building Code | Number of Coats and Total Thickness
9.28.6.2. Number of Coats and Total Thickness
(1) stucco shall be applied with at least two base coats and one finish coat, providing a total thickness of not less than 15 mm, measured from the face of the lath or face of the masonry where no lath is used.
In Plain Language
Stucco must be applied in the number of coats and total thickness set out in this article, since a multi-coat system builds the strength and crack resistance that a single thick coat can't achieve.
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.