Ontario Building Code Standards for Wood Shakes and Built-Up Roofs | London, Ontario
Sarah's Expert Insight
OBC Compliance Specialist
"In regions like London and Muskoka, the integrity of wood shake spacing and bitumen ratios is critical for surviving Ontario’s extreme freeze-thaw cycles. At empcontracting.ca Inc. your construction contractor in London, Ontario, we strictly enforce the 'no-mix' rule for coal-tar and asphalt to prevent chemical degradation, ensuring your roof remains under warranty and structurally sound for decades."
Understanding the technical requirements of the 2024 Ontario Building Code (OBC) is essential for any high-quality roofing project. As empcontracting.ca Inc. your construction contractor in London, Ontario, we ensure every installation adheres to these rigorous safety and durability standards.
Section 9.26.10: Wood Shake Installation Requirements
Wood shakes provide a classic aesthetic but require precise installation to manage moisture and expansion.
Spacing, Fastening, and Joints
- Spacing: Shakes must be spaced between 6 mm and 9 mm apart to account for material swelling.
- Joint Separation: Joints in any one course must be separated by at least 40 mm from joints in adjacent courses.
- Fastening: Nails should be located approximately 20 mm from the sides and 40 mm above the exposure line.
Exposure and Material Grade
OBC 9.26.10.5 mandates that exposure must not exceed 190 mm for 450 mm shakes or 240 mm for 600 mm shakes. Furthermore, only No. 1 or Handsplit grade shakes are permitted for use under code 9.26.10.8.
Section 9.26.11: Built-Up Roof Systems
Built-up roofing (BUR) standards are governed by strict material quantities and compatibility rules to ensure water-tight performance.
Bitumen Quantities and Application
The amount of bitumen applied per square metre is determined by the roof type. For example, asphalt and aggregate roofs require 1 kg for mopping coats and 3 kg for the flood coat. Professional application ensures these layers provide the necessary thermal and moisture protection.
Material Compatibility
It is a critical violation of OBC 9.26.11.2 to use coal-tar products and asphalt products together in a built-up roof construction, as chemical incompatibility can lead to system failure.
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.