Designed for any style roof & lays flatter with less air pockets than traditional felt 60 day UV exposure Water Resistant Coverage (with 2in. Lap): 10 square Coverage (with 4" Lap): 917 Square Feet Dimensions: 250ft. (l) x 48in. (w) The Atlas Summit S60 Synthetic Felt offers large surface area placement with each roll covering 10 square (1000 square feet). The high UV exposure allows for the underlayment to be laid, walked on, exposed to rain without any damage to your home. The slip resistant coating prevents falls when applied while the roof is being added. Unique Top Surface Fabric Allows for Enhanced Walkability. Meets ASTM D6757, Inorganic Shingle Underlayment. Standard Performance Characteristics. Exceed ASTM D4869 & D226. Florida Building Code Approved - FL 16226. UL Classified.