The Ontario Building Code | Protection from Weather
9.20.14.2. Protection from Weather
(1) The top surface of uncompleted masonry exposed to the weather shall be completely covered with a waterproofing material when construction is not in progress.
9.20.15. Reinforcement for Earthquake Resistance
In Plain Language
Newly laid masonry must be protected from weather as set out in this article, shielding fresh mortar from rain, freezing, or excessive drying before it has cured.
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.