Single ply roof guarantees, usually 15-20 years, cover defects but don’t always...

https://andreocln282.lucialpiazzale.com/pvc-single-ply-roof-lifespan-is-30-years-realistic

Single ply roof guarantees, usually 15-20 years, cover defects but don’t always reflect the roof’s full lifespan, which can be 25-40 years with proper care. To help your roof reach its potential, arrange annual inspections and clear drains regularly