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

https://telegra.ph/Incompatible-Adhesives-on-Single-Ply-Roofs---What-Happens-07-31

Single ply roof guarantees typically cover 15-20 years, but the actual service life can stretch up to 25-40 years if the roof is properly maintained. Guarantees focus on materials and installation, not wear from weather or blocked drains