2024 Ontario Building Code: Standards for Masonry Foundation Walls and Beam Support
Sarah's Expert Insight
OBC Compliance Specialist
"In my experience consulting on projects across London, Oakville, and Muskoka, the 190mm solid masonry requirement under beams is frequently overlooked but vital for preventing localized crushing. At empcontracting.ca Inc. your construction contractor in London, Ontario, we pay particular attention to crack control joints in larger residential foundations to mitigate the effects of the region's seasonal freeze-thaw cycles."
Navigating the 2024 Ontario Building Code (OBC) is essential for ensuring structural integrity and compliance. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize these technical requirements to deliver safe and durable foundations for every project.
9.15.4 Foundation Wall Specifications
Masonry Facing and Corbelling
Per OBC 9.15.4.7, when the top of a foundation wall is reduced to accommodate masonry exterior facing, the remaining section must be at least 90 mm thick. These sections must be tied using specific metal ties spaced no more than 200 mm vertically and 900 mm horizontally. Furthermore, the space between the wall and the facing must be completely filled with mortar to ensure structural unity.
Crack Control Joints
For large-scale builds, crack control joints are mandatory in foundation walls exceeding 25 meters in length. These joints must be placed at intervals of no more than 15 meters and designed to resist moisture penetration while being keyed to prevent relative displacement between wall sections.
9.15.5 Support of Joists and Beams
Floor Joist Support and Capping
Hollow masonry units supporting floor joists require capping with at least 50 mm of concrete or solid masonry units. However, exceptions apply in London and other Ontario localities where termites are not a known threat, provided the joists sit on a 38 mm x 89 mm wood plate and the siding overlaps the foundation by at least 12 mm.
Structural Support for Beams
According to Article 9.15.5.2, beams supported on masonry must have at least 190 mm of solid masonry beneath them. If a beam is supported below the top of the foundation wall, the ends must be protected from weather exposure to prevent rot and structural degradation.
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.