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

https://meet-wiki.win/index.php/Do_Certified_Installers_Really_Make_a_Roof_Last_Longer%3F

Single ply roof guarantees often cover 15-20 years, but the real service life can stretch to 25-40 years if looked after properly. Guarantees focus on materials and workmanship, not wear and tear or maintenance issues