Single ply roof guarantees usually cover 15-20 years, but the real service life...

https://devinzort649.timeforchangecounselling.com/how-do-seams-fail-on-single-ply-roofs-over-time

Single ply roof guarantees usually cover 15-20 years, but the real service life can stretch well beyond that, often 25-40 years. Guarantees focus on material faults, while actual lifespan depends on maintenance, weather, and installation