Quick Roof Extreme is guaranteed not to crack, harden or shrink. It instantly stops leaks and permanently repairs all RV roof materials, vents, skylights, slideouts, windows, awnings, holding tanks, tents and more. Can be applied to most materials when damp or even went. Permanently repairs EPDM, TPO, metal, fiberglass, aged and rigid PVC, vinyl, wood, OSB and most building materials.