Best Commercial Roofing Contractors in London

Commercial and industrial roofing in London covers offices, retail centres, warehouses, and multi-unit buildings — most using low-slope membrane systems such as TPO, EPDM, and modified bitumen. The 6 contractors below were selected from our full London top 10 as the strongest for commercial work, ranked by experience, manufacturer certifications, BBB standing, and verified reputation.

London, Ontario's commercial roofing market reflects the city's dual character as a mid-sized manufacturing and health-care hub with a growing post-secondary campus presence. Office parks along Wellington and Exeter Roads, industrial facilities in the east end, and institutional buildings at Western University create a diverse commercial roofing demand that spans TPO single-ply on new construction, EPDM replacement on mid-century flat-roofed industrial blocks, and modified bitumen maintenance on the city's retail plazas.

London's climate sits in a Lake Erie-influenced precipitation corridor where annual snowfall is significant and summer convective storms deliver periodic high-wind and hail events. Commercial building owners in London face the specific challenge of scheduling roof replacements around Ontario winter conditions while managing occupied-building disruption. The most experienced commercial roofers in the London market understand both the technical membrane assembly requirements and the operational scheduling constraints of active commercial properties.

How many commercial roofing contractors are in London?

Our directory lists 6 independently verified commercial roofing contractors serving London, Ontario, ranked by experience, certifications and reputation. AM Group Exteriors (AM Roofing Solutions) is ranked #1. There are no paid placements.

How do I choose a commercial roofer in London?

Confirm licensing and insurance for Ontario, ask for commercial project references in London, get multiple written quotes, and check each contractor's BBB standing. Every company listed here has been independently researched.

What commercial membrane systems are most common in London, Ontario?

TPO single-ply is the current market leader for new commercial construction and replacement projects in London, valued for its heat-weldable seams, white reflective surface, and broad contractor familiarity. EPDM remains common on replacement projects where existing assemblies used that system. Modified bitumen — both torch-applied and cold-applied — is the standard on older commercial buildings originally built with built-up roofing, where a like-for-like replacement is often the path of least resistance.

Does commercial roofing in Ontario require specific certifications or permits?

Commercial roofing projects in London require building permits from the City of London for most replacement and new construction work. Contractors must comply with Ontario's occupational health and safety regulations governing work at heights, including the use of fall protection equipment and associated site procedures. Institutional and government projects often require additional procurement documentation, WSIB clearance certificates, and proof of adequate commercial liability coverage.

How should I evaluate competing bids for a London commercial roofing project?

Beyond unit pricing, evaluate bids on membrane manufacturer certification level, warranty terms (workmanship versus manufacturer-backed), stated drainage and tapered insulation design approach, and the contractor's track record on projects of comparable size in the London market. Substantially lower bids often reflect reduced insulation thickness, thinner membrane specifications, or reduced seam quality standards that affect long-term performance rather than up-front installation differences.