The Ontario Building Code | Maximum Size of Opening
9.10.13.8. Maximum Size of Opening
(1) The size of an opening in an interior fire separation, even where protected with a closure, shall not exceed 11 m², with no dimension greater than 3.7 m, if a fire compartment on either side of the fire separationis not sprinklered.
(2) The size of an opening in an interior fire separation, even where protected with a closure, shall not exceed 22 m², with no dimension greater than 6 m, when the fire compartments on both sides of the fire separation are sprinklered.
In Plain Language
The maximum size of an opening protected by a closure is set out in this article, since fire doors and similar assemblies are only rated up to a certain tested size.
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.