Single ply roof guarantees often promise 15-20 years, but the real service life...

https://www.bookmark-help.win/single-ply-roof-guarantees-typically-cover-15-20-years-but-these-roofs-can

Single ply roof guarantees often promise 15-20 years, but the real service life can stretch to 25-40 years if looked after properly. These guarantees cover material defects, not wear and tear from weather or poor maintenance