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

https://www.first-bookmarkings.win/single-ply-roof-guarantees-often-cover-15-20-years-but-the-real-service-life

Single ply roof guarantees often cover 15-20 years, but the actual service life can stretch 25-40 years with good care. Guarantees mainly cover manufacturing defects, not wear and tear or maintenance lapses