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

https://www.third-bookmarks.win/single-ply-roof-guarantees-usually-cover-15-20-years-but-these-membranes-often

Single ply roof guarantees usually cover 15-20 years, but the real service life often stretches to 25-40 years. That’s because guarantees focus on material faults, not wear from weather or maintenance issues