The Ontario Building Code | Mezzanines
9.10.8.6. Mezzanines
(1) Mezzanines required to be counted as storeys in Articles 9.10.4.1. and 9.10.4.2. shall be constructed in conformance with the requirements for "floors Except floors over Crawl Spaces" in Table 9.10.8.1.
In Plain Language
Mezzanines have fire-resistance rating requirements set out in this article, addressing their structural separation from the space below in buildings where fire rating matters.
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.