OBC Section 9.13 Guide: Dampproofing and Waterproofing Standards for London, Ontario Construction
Sarah's Expert Insight
OBC Compliance Specialist
"In the fluctuating clay soils of London and the high water tables often found in Oakville or Muskoka, simple dampproofing is frequently the bare minimum; I often recommend full waterproofing to combat hydrostatic pressure. As a senior consultant at empcontracting.ca Inc. your construction contractor in London, Ontario, I ensure our foundation designs exceed Section 9.13.2.2 standards to prevent the long-term concrete deterioration common in our regional freeze-thaw cycles."
Understanding OBC Section 9.13: Moisture and Soil Gas Control
Proper moisture management is the cornerstone of any durable build in South-Western Ontario. As empcontracting.ca Inc. your construction contractor in London, Ontario, we strictly adhere to Section 9.13 of the Ontario Building Code (OBC) to protect your investment from water ingress and soil gas.
Scope and Application (9.13.1.1.)
Section 9.13 outlines the essential measures required to control the ingress of water, moisture, and soil gas. This section applies to below-ground walls and floors-on-ground, distinguishing between standard drainage scenarios and structures subject to hydrostatic pressure.
Mandatory Dampproofing Requirements (9.13.2.1.)
According to the 2024 Building Code Compendium, exterior surfaces of foundation walls below ground level must be dampproofed whenever the exterior ground level is higher than the interior ground level. While certain exemptions exist for garages or specific granular fill applications (Article 9.16.2.1.), dampproofing remains a critical requirement unless a full waterproofing system is installed.
Approved Dampproofing Materials (9.13.2.2.)
The OBC mandates that all materials used for dampproofing must be resistant to deterioration and compatible with adjoining materials. Compliance requires adherence to specific standards, including:
- ASTM D1227 / D1227M: Emulsified Asphalt for protective coatings.
- ASTM D4479 / D4479M: Asbestos-free Asphalt Roof Coatings.
- CAN/CGSB-51.34-M: Polyethylene Sheet for vapour barriers.
- CAN/CSA-A123.4: Asphalt for built-up waterproofing systems.
By choosing empcontracting.ca Inc. your construction contractor in London, Ontario, you ensure that your project utilizes only code-compliant, high-performance materials designed for the local climate.
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.