Ontario Building Code (OBC) 2024: Masonry Veneer and Wall Construction Standards
Sarah's Expert Insight
OBC Compliance Specialist
"Proper air space management in masonry veneer is the single most important factor in preventing long-term moisture damage and freeze-thaw issues in Southwestern Ontario's fluctuating climate. As a senior consultant at empcontracting.ca Inc. your construction contractor in London, Ontario, I advise clients in London, Oakville, and Muskoka to strictly adhere to these thickness and spacing rules to protect the structural envelope of their property against harsh lakefront winds and urban conditions."
Understanding the technical requirements of the 2024 Ontario Building Code (OBC) is vital for ensuring the structural integrity and longevity of any masonry project. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize these standards to deliver superior craftsmanship for residential and commercial developments.
9.20.6.4. Masonry Veneer Specifications
Proper veneer installation is essential for weatherproofing and aesthetic durability. The code outlines specific thickness and drainage requirements:
Veneer Thickness and Air Space
- Solid masonry units must be at least 70 mm thick, unless individual supports are provided for each unit.
- A minimum 25 mm air space is mandatory behind veneers installed over wood-frame walls to facilitate moisture drainage.
- Unraked joints are required for masonry veneers less than 90 mm thick to maintain structural stability.
9.20.6.5. Parapet Walls and Facings
Parapet walls must be constructed to withstand environmental pressures and lateral loads:
Height and Structural Continuity
- The height of a parapet wall above the roof surface must not exceed three times its thickness.
- Solid masonry must be used, extending from the top of the parapet to at least 300 mm below the adjacent roof level.
- Hollow or semi-solid units used in parapets must have their cells filled with mortar, grout, or concrete for added strength.
9.20.7. Chases and Recesses
Cutting or building recesses into masonry walls can compromise strength if not performed according to code. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure all utility chases follow these safety margins:
Maximum Dimensions and Separation
- The depth of any chase or recess cannot exceed one-third of the wall thickness, and the width is limited to 500 mm.
- Wall thickness must typically be at least 190 mm to permit any chase construction.
- Recesses must be separated by at least 4 times the wall thickness and must remain at least 600 mm away from vertical supports like pilasters or buttresses.
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.