2024 Ontario Building Code: Expert Guide to Roofing and Wall Drainage in London, Ontario
Sarah's Expert Insight
OBC Compliance Specialist
"In regions like London and Muskoka, the 2024 OBC requirements for ice damming protection and ventilated wall cavities are critical due to our intense freeze-thaw cycles. As a senior consultant at empcontracting.ca Inc., your construction contractor in London, Ontario, I ensure our projects exceed the 10mm drainage minimum to mitigate the long-term risk of mold and moisture entrapment common in Southwestern Ontario's climate."
Understanding the complexities of the 2024 Building Code Compendium is essential for any high-quality build. At empcontracting.ca Inc. your construction contractor in London, Ontario, we prioritize compliance to ensure your structure is durable, safe, and efficient.
Wall Drainage and Ventilation Standards (OBC 9.25.5.2)
According to Section 9.25.5.2., walls must feature an air space that is both drained and ventilated. This space must be at least 10 mm deep behind the cladding, extending over the full height and width of the wall to prevent moisture buildup and structural degradation.
Roofing Requirements Under Section 9.26
9.26.1. General Definitions and Protection
The OBC defines a "roof" as any sloped or near-horizontal assembly protecting the space beneath it, including platforms used for precipitation drainage. The primary mandate for any roof installed by empcontracting.ca Inc. is to effectively shed water and prevent moisture ingress into building assemblies, with a specific focus on minimizing ice damming.
9.26.1.3. Alternate Installation and Modern Solar Systems
Contractors may utilize CSA A123.51 standards for asphalt shingle application on steeper slopes. Furthermore, the 2024 code explicitly permits the installation of solar collector systems above approved roofing materials, provided they meet the material standards outlined in Sentence 9.26.2.1.(1).
9.26.2. Roofing Material Standards
All materials used for the substrate or the primary roofing covering must conform to the specific standards listed in Tables 9.26.2.1.-A and 9.26.2.1.-B. Using certified materials is a non-negotiable aspect of professional construction management in Ontario.
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.