Products / Owens Corning RhinoRoof U20 Synthetic Underlayment

RhinoRoof U20 is a synthetic roofing underlayment with a fiber-grip top surface and a back coating for deck adhesion, for use under asphalt and composite shingles, residential metal and primed cedar shake but not under tile. The brochure gives a 10-square roll of 286 ft. x 42 in. weighing 23.5 lbs., up to 90 days of UV exposure before it must be covered, and a 20-year limited warranty; below 2:12 it is not recommended, and from 2:12 to under 4:12 it goes down in two layers. It is marketed with RhinoRoof Granulated as an eave-to-peak underlayment system, and its Class A fire rating under ASTM E108/UL 790 applies when installed under asphalt shingles.