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

https://www.bookmark-step.win/single-ply-roof-guarantees-usually-last-15-20-years-but-the-actual-roof-can

Single ply roof guarantees often cover 15-20 years but the real service life can stretch to 25-40 years. The difference usually comes down to maintenance and installation quality