The Ontario Building Code | Walls and Ceilings in Bathrooms
9.10.17.11. Walls and Ceilings in Bathrooms
(1) The interior finish of walls and ceilings in bathrooms within suitesof residential occupancy shall have a surface flame-spread rating of not more than 200.
In Plain Language
Walls and ceilings in bathrooms have specific flame-spread requirements set out in this article, an exception area given the smaller room size and different finish materials typically used there.
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.