Single ply roofing guarantees typically span 15-20 years, covering material...

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

Single ply roofing guarantees typically span 15-20 years, covering material defects but not the entire roof’s life. In reality, with good care, these roofs can last 25-40 years