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

https://www.bust-bookmark.win/single-ply-roof-guarantees-typically-15-20-years-cover-defects-but-not-the

Single ply roof guarantees usually cover 15-20 years, but the actual service life can stretch much longer, often 25-40 years. The key difference is that guarantees focus on materials and workmanship, not ongoing upkeep