The Ontario Building Code | Termination of Floors or Mezzanines
9.10.12.1. Termination of floors or Mezzanines
(1) Except as provided in Sentence (2) and in Articles 9.10.1.3. and 9.10.9.5., the portions of a floor area or mezzaninethat do not terminate at an exterior wall, a firewallor a vertical shaft, shall terminate at a vertical fire separation having a fire-resistance ratingnot less than that required for the floor assembly that terminates at the separation.
(2) Amezzanine need not terminate at a vertical fire separation where the mezzanineis not required to be considered as a storey in Articles 9.10.4.1. and 9.10.4.2.
In Plain Language
Where a floor or mezzanine terminates near an opening such as a stairwell, this article sets out the specific fire safety requirements that apply at that termination point.
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.