Single ply roof guarantees, usually 15-20 years, cover specific materials and...

https://wiki-site.win/index.php/IKO_Group_Single_Ply_Lifespan_Claims_%E2%80%93_What_Do_They_Actually_Say%3F

Single ply roof guarantees, usually 15-20 years, cover specific materials and workmanship under set conditions, but real service life often extends to 25-40 years with proper care