Spray foam is one of the most regulated insulation products in Ontario — and that's a good thing. Here's what the Ontario Building Code requires, and what your inspector will look for.
Material and Installer Standards
Medium-density closed-cell spray foam must comply with CAN/ULC-S705.1 (material standard), and installation must follow CAN/ULC-S705.2 (installation standard). That second one matters: it requires installers to be certified, to verify substrate temperatures, to apply in proper lift thicknesses, and to document the job with daily work records.
When a GC asks us for documentation, this is what we hand over — installer certification, product data sheets, and application records that map to S705.2.
Thermal Barriers
Spray foam is combustible and generally must be protected from living spaces by a thermal barrier — typically 12.7 mm drywall or an approved intumescent coating. Attics and crawl spaces have specific provisions. This is the requirement DIY and low-bid installs miss most often, and it's an automatic inspection failure.
Vapour Barrier Compliance
Closed-cell foam at sufficient thickness (typically 50 mm) acts as its own vapour barrier, which is why basements and rim joists sprayed with closed-cell don't need poly. Your inspector will verify thickness — we spray to spec and provide spot-check records on request.
Code details change with amendments, and specific assemblies have specific requirements. If you're planning a project and want to know exactly what applies, get in touch — we deal with this daily.