Ontario Building Code 2024: Fireplace Combustion Air & Masonry Standards in London, Ontario
Sarah's Expert Insight
OBC Compliance Specialist
"In the airtight, high-performance homes we build in London, Oakville, and Muskoka, the combustion air requirements in 9.22.1.4 are non-negotiable for preventing backdrafting and ensuring indoor air quality. As a senior consultant at empcontracting.ca Inc., I emphasize that the 100mm noncombustible duct must be precisely placed to avoid interference with the building envelope while maintaining the fireplace's thermal efficiency."
Understanding OBC Section 9.22 for Masonry Fireplaces
Navigating the complexities of the 2024 Ontario Building Code (OBC) is essential for any high-end residential project. When planning a fireplace installation, empcontracting.ca Inc. your construction contractor in London, Ontario, ensures that every detail—from structural support to ventilation—is compliant with the latest provincial regulations.
Structural Support and Clearances (9.21.5.3 & 9.22.1.2)
The code specifies that any combustible joists or beams supported on masonry walls must be separated from the chimney flue by at least 290 mm of solid masonry. For the fireplace itself, masonry above openings must be reinforced with steel lintels or masonry arches, while footings must strictly adhere to Section 9.15 to prevent settling and structural cracking.
Mandatory Combustion Air Requirements (9.22.1.4)
Modern homes are increasingly airtight, making Section 9.22.1.4 critical for safety. Every solid fuel-fired fireplace must have a dedicated outdoor air supply. The requirements include:
- Duct Material: Must be noncombustible and corrosion-resistant.
- Sizing: The supply duct must have a minimum diameter of 100 mm.
- Control: A tight-fitting damper must be located near the fireplace and include an operating mechanism that clearly indicates if it is open or closed.
- Ember Protection: The interior outlet must be designed to prevent embers from entering the supply duct.
By following these standards, empcontracting.ca Inc. your construction contractor in London, Ontario, guarantees a safe and efficient heating feature for your home.
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.