OBC 2024 Guide: Fire Damper and 20-Minute Closure Standards for London, Ontario
Sarah's Expert Insight
OBC Compliance Specialist
"In my experience at empcontracting.ca Inc., the 610 mm rule for combination dampers and the requirement for 1.5 m smoke detector proximity are the most frequent points of failure during inspections in London and Oakville. Properly sizing and positioning access doors is not just a code requirement—it's a liability safeguard for property owners across Ontario's multi-residential and commercial sectors."
Navigating the complexities of the 2024 Building Code Compendium is essential for maintaining safety and compliance in modern developments. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure every installation meets these rigorous life-safety requirements.
3.1.8.10. Installation of Fire Dampers
Fire dampers are critical safety components that must be installed precisely in the plane of the fire separation. This ensures they remain functional even if the surrounding ductwork is compromised during a fire event.
Automatic Operation and Thermal Ratings
Dampers must close automatically via fusible links or heat/smoke-actuated devices. Heat-actuated devices must have a temperature rating approximately 30°C above the maximum system operating temperature to prevent nuisance tripping while ensuring rapid response during an actual fire.
3.1.8.11. Installation of Smoke Dampers
Smoke dampers used in air-transfer openings must be installed in the plane of the fire separation. For combination smoke/fire dampers, the code allows for installation within 610 mm of the plane, provided there are no intermediate openings.
Sensor Placement and Access Requirements
Automatic closure must be triggered by smoke detectors located within 1.5 m of the duct or air-transfer opening. Furthermore, the OBC mandates tightly fitted access doors for every damper to facilitate regular inspection and resetting, a service empcontracting.ca Inc. your construction contractor in London, Ontario provides to ensure long-term building integrity.
3.1.8.12. Twenty-Minute Closures
The code permits 20-minute fire-protection rated door assemblies in specific scenarios, primarily within fire separations not exceeding 1 hour. This applies to transitions between public corridors and suites, or corridors leading to classrooms and offices in Group A occupancies. Additionally, 20-minute closures are acceptable in buildings up to 3 storeys where a 45-minute fire-resistance rating is required.
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.