Single ply roof guarantees typically cover 15-20 years, reflecting the...

https://www.bright-bookmarks.win/single-ply-roof-guarantees-usually-last-15-20-years-focusing-on-the-product

Single ply roof guarantees typically cover 15-20 years, reflecting the manufacturer’s confidence in materials, not the full service life, which can stretch to 25-40 years with proper care