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

https://www.strobe-bookmarks.win/single-ply-roof-guarantees-typically-cover-15-20-years-but-the-real-service

Single ply roof guarantees typically cover 15-20 years, focusing on material defects and workmanship. However, the actual service life can stretch well beyond 25-40 years with proper care