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

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

Single ply roof guarantees usually cover 15-20 years, but the actual roof can last 25-40 years with good care. Guarantees often focus on materials, not wear and tear or damage from poor maintenance