2024 Ontario Building Code Firestop and Closure Ratings | empcontracting.ca Inc.
Sarah's Expert Insight
OBC Compliance Specialist
"Navigating the complexities of FT and F ratings is essential for high-density residential projects in London and Oakville to avoid inspection failures. At empcontracting.ca Inc., we prioritize the precise application of Table 3.1.8.4 to ensure all fire closures and smoke dampers provide maximum protection and full OBC compliance for our clients."
Understanding Firestops and Joint Seals in the 2024 OBC
In accordance with the latest Ontario Building Code (OBC) regulations, maintaining the integrity of fire separations is a critical safety requirement. When you partner with empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that every firestop required by Sentence (2) meets the mandatory FT rating. This rating must not be less than the fire-resistance rating of the abutting fire separation, as verified by the CAN/ULC-S115 fire test method.
Perimeter Fire Barrier Standards
For joints located in a horizontal plane—specifically those between a floor and an exterior wall—contractors must use firestops that meet the F rating requirements under the ASTM E2307 standard. Exceptions are permitted under Sentence (5) where joints consist of gypsum board framing designed to restrict the passage of flame and smoke.
Determination of Ratings for Closures
Article 3.1.8.4 specifies that the fire-protection rating of closures, such as doors and windows, must be determined via specific standard methods, including CAN/ULC-S104 and CAN/ULC-S106. For modern construction in London and surrounding areas, smoke dampers must also conform to leakage rate standards Class I, II, or III under CAN/ULC-S112.1.
OBC Table 3.1.8.4: Fire-Protection Rating of Closures
| Fire-Resistance Rating of Fire Separation | Min. Fire-Protection Rating of Closure |
|---|---|
| 30 min | 20 min |
| 45 min | 45 min |
| 1 h | 45 min |
| 1.5 h | 1 h |
| 2 h | 1.5 h |
| 3 h | 2 h |
| 4 h | 3 h |
Disclaimer: This content is generated from the Ontario Building Code for educational purposes. Always consult with a licensed professional engineer or your local building department before starting any construction project in London, Ontario.