2024 Ontario Building Code (OBC) Section 9.38: Guide to Log Construction Standards
Sarah's Expert Insight
OBC Compliance Specialist
"In my years of consulting across London, Oakville, and Muskoka, I have seen that the most common oversight is the plate width requirement for vertical logs under 9.38.2.5. At empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure that every log is correctly scribed and plated to prevent the structural settling issues that often plague poorly executed log builds in Ontario’s variable climate."
Introduction to OBC Log Construction Requirements
Building with logs in Ontario requires strict adherence to the 2024 Building Code Compendium to ensure structural safety and moisture protection. Whether you are constructing a seasonal cottage or a permanent residence, Section 9.38 provides the roadmap for compliant log assembly. For expert guidance, consult with empcontracting.ca Inc. your construction contractor in London, Ontario.
9.38.1 General Material and Structural Requirements
All logs utilized in foundations, beams, and posts must be sound and free of fractures. Structural adequacy must be verified through analysis, testing, or documented previous experience. To prevent decay, any log in contact with concrete or masonry at or below grade must be treated with an approved wood preservative. Furthermore, exterior joints must be rendered water-tight using methods such as machined joints, chinking, or caulking to protect the building envelope.
9.38.2 Walls and Jointing Specifications
Log walls can be built using natural or manufactured logs. For horizontal log configurations, the code mandates interlocking intersections or vertical corner posts to prevent water pooling in joints. Logs must be scribed as closely as possible to their bearer and fastened in at least three places, with fastenings spaced no further than 1800 mm apart.
9.38.2.4 Vertical Log and Plate Standards
Vertical log construction requires each log to be scribed to fit adjacent logs tightly. A critical requirement under 9.38.2.5 is the installation of top and bottom plates. These plates must be at least as wide as the largest end diameter of any log in the wall to ensure proper load distribution and structural alignment.
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.