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

https://wiki-fusion.win/index.php/If_My_Guarantee_Expired,_Does_That_Mean_My_Roof_Is_Done%3F

Single ply roof guarantees usually cover 15-20 years, but the actual service life often stretches to 25-40 years. That’s because guarantees focus on materials, not wear and tear or maintenance