How many commercial roofing contractors are in Toronto?
Our directory lists 8 independently verified commercial roofing contractors serving Toronto, Ontario, ranked by experience, certifications and reputation. Dominion Roofing is ranked #1.
How do I choose a commercial roofer in Toronto?
Confirm licensing and insurance for Ontario, ask for commercial project references in Toronto, get multiple written quotes, and check each contractor's BBB standing. Every company listed here has been independently researched.
Does Toronto's Green Roof Bylaw apply to re-roofing projects?
The Green Roof Bylaw applies to new building permit applications — typically triggered when more than 50% of a building's value is being added or altered. A straightforward like-for-like re-roofing of an existing commercial building generally does not trigger the bylaw. However, any addition, major renovation, or change of use that requires a full building permit review may trigger compliance. The City of Toronto's Building Division can confirm applicability for your specific project before permit application.
What insulation R-value is required for commercial roofs in Toronto?
Ontario's Building Code (OBC 2024) requires a minimum RSI-5.5 (approximately R-31) effective thermal resistance for commercial roof assemblies in Toronto's climate zone. This is typically achieved with 5–6 inches of polyisocyanurate insulation board, derated for cold-weather performance. The code's effective R-value requirement means the complete assembly — including structural deck and air barrier — is assessed together. GTA contractors familiar with RoofNav assembly specification tools can generate code-compliance documentation as part of the project package.
How long does a commercial roof replacement take in Toronto's dense urban environment?
A typical suburban Toronto commercial roof replacement on a 20,000 sq ft building takes five to ten working days in good weather. Downtown core projects take significantly longer due to crane permit timelines (Toronto Right-of-Way permits can take two to four weeks to obtain), staging constraints, noise by-law compliance windows (construction typically restricted to 7am–7pm weekdays), and union contract requirements. Building owners with lease revenue at risk should account for extended timelines and negotiate contractor scheduling commitments in writing before signing.