Single ply roof guarantees, usually 15-20 years, cover material faults but...

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

Single ply roof guarantees, usually 15-20 years, cover material faults but don’t always reflect the roof’s true lifespan, which can last 25-40 years with proper care. The difference? Maintenance