Single ply roof guarantees typically cover 15-20 years, focusing on material...

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 typically cover 15-20 years, focusing on material defects or installation issues. But the actual service life can stretch 25-40 years if the roof is well maintained