The Ontario Building Code | Fire-Resistance Ratings for Floors and Roofs
9.10.8.1. Fire-Resistance Ratings for floors and Roofs
(1) Except as otherwise provided in this Subsection, the fire-resistance ratings of floors and roofs shall conform to Table 9.10.8.1.
Table 9.10.8.1.
Fire Resistance Ratings for Structural Members and Assemblies
Forming Part of Sentence 9.10.8.1.(1)
| Item | Column 1 | Column 2 | Column 3 | Column 4 | Column 5 |
|
| Major Occupancy | Maximum building Height, Storeys | Minimum Fire-Resistance Rating by Building Element, min | ||
|
|
| Floors Except Floors over Crawl Spaces | Mezzanine Floors | Roofs | |
| 1. | Residential (Group C) | 3 | 45 | 45 | — |
| 2. | All other occupancies | 2 | 45 | — | — |
| 3 | 45 | 45 | 45 | ||
In Plain Language
Floors and roofs must achieve the fire-resistance ratings set out in this article, ensuring these horizontal assemblies can contain fire and maintain structural support long enough for safe evacuation.
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.