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

https://www.red-bookmarks.win/single-ply-roof-guarantees-usually-cover-15-20-years-but-the-actual-service

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