Single ply roof guarantees, typically 15-20 years, cover manufacturer...

https://remote-wiki.win/index.php/Is_It_Worth_Paying_More_Upfront_to_Get_35_Years_Instead_of_14%3F

Single ply roof guarantees, typically 15-20 years, cover manufacturer defects—but real service life often stretches to 25-40 years with proper care. The key difference is how well the roof’s maintained