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

https://www.bookmark-belt.win/single-ply-roof-guarantees-usually-cover-15-20-years-but-the-actual-roofing

Single ply roof guarantees usually cover 15-20 years, but the actual service life often runs between 25-40 years. That’s because guarantees focus on material defects, not wear and tear from daily weather or poor maintenance