Single ply roof guarantees often cover 15-20 years, but the roof can last 25-40...

https://www.bookmarking-online.win/single-ply-roof-guarantees-usually-cover-15-20-years-but-the-roofs-often-last

Single ply roof guarantees often cover 15-20 years, but the roof can last 25-40 years with the right care. Guarantees typically focus on materials, not wear and tear or maintenance