Single ply roof guarantees usually cover 15-20 years, reflecting the...

https://www.slideserve.com/gwyneyxcez/why-do-roof-problems-show-up-after-two-winters

Single ply roof guarantees usually cover 15-20 years, reflecting the manufacturer's confidence in the materials but not the full lifespan. In reality, these roofs can last 25-40 years if properly cared for