A well-installed TPO roof typically lasts 20 to 30 years in Ontario. But that range is wide for a reason — four things decide where your roof lands in it.
TPO comes in 45, 60, and 80 mil thicknesses. Thicker membrane resists punctures and weathering longer. For commercial roofs with foot traffic (HVAC servicing, etc.), 60 mil or higher is usually worth the small upcharge.
London swings across the freezing point dozens of times each winter. Every cycle stresses seams and flashing. Quality heat-welded seams — not tape — are what keep a TPO roof watertight through that cycle for decades.
The membrane rarely fails first; the details do — flashing, drains, and penetrations. This is why manufacturer-certified installation matters, and why the cheapest quote often costs more over the roof's life.
Roofs on a maintenance plan reliably outlast neglected ones by years, and documented maintenance is often required to keep the warranty valid. Small fixes caught early prevent the leaks that shorten a roof's life.
Specify adequate membrane thickness, insist on certified installation, and maintain it. Do that and 25+ years is realistic. Thinking about TPO or EPDM for your building, or planning a full replacement? We'll give you an honest assessment.