Single ply roof guarantees often cover 15-20 years but the real service life...

https://hectoruwog494.image-perth.org/single-ply-vs-epdm-which-one-lasts-longer-on-a-warehouse

Single ply roof guarantees often cover 15-20 years but the real service life can stretch to 25-40 years. The difference usually comes down to maintenance and installation quality