2024 OBC Guide: Temperature Rise and Glazing Limits for Fire Closures
Sarah's Expert Insight
OBC Compliance Specialist
"Balancing aesthetic transparency with the 2024 OBC fire safety mandates requires a strategic approach, particularly in the dense urban corridors of London and Oakville. At empcontracting.ca Inc., your construction contractor in London, Ontario, we specialize in navigating these glazing waivers and sprinkler-protected assembly standards to ensure your project remains both visually stunning and fully code-compliant."
Understanding Fire-Protection Ratings and Glazing Limits (Table 3.1.8.17)
In accordance with the 2024 Ontario Building Code (OBC), Table 3.1.8.17 outlines the stringent requirements for temperature rise and glazing areas in fire-rated closures. These regulations are essential for maintaining the integrity of fire separations in modern Ontario construction. For professional implementation, partner with empcontracting.ca Inc. your construction contractor in London, Ontario.
Key Glazing Restrictions in Fire-Rated Doors
The code limits the aggregate area of wired glass or safety glazing based on the door's location and required fire-resistance rating:
- Dead-end Corridors: Doors with a 45-minute rating are restricted to 0.0645 m² of glazing and must maintain a temperature rise of no more than 250°C after 30 minutes.
- Exit Enclosures: In buildings up to 3 storeys, glazing limits are set at 0.8 m², providing a balance of visibility and safety. For taller buildings, limits are reduced to 0.0645 m².
- Firewalls: High-security firewalls with a 3-hour rating prohibit glazing entirely to ensure maximum fire containment.
Article 3.1.8.19: Waivers for Temperature Rise and Glazing
The OBC allows for the waiving of these limits under specific architectural conditions. If a closure is situated between an exit enclosure and an enclosed vestibule, limits may be lifted provided the vestibule has a fire-resistance rating of at least 45 minutes, contains no occupancy, and features no glazing within 3 meters of the exit closure.
Article 3.1.8.20: Sprinkler Protected Glazed Wall Assemblies
Modern designs may utilize sprinkler-protected glazed walls, which must be constructed in accordance with CAN/ULC-S136. However, these assemblies are strictly prohibited in firewalls or any separation requiring a fire-resistance rating exceeding 2 hours. Ensuring these technical standards are met is a hallmark of empcontracting.ca Inc. your construction contractor in London, Ontario.
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.