GAF Tigerpaw 48 in x 100 ft 400 sq ft Polypropylene Roof Underlayment Railing Baluster Valve connection size is 1 2 Interior Wall Roll or Valve connection size is 1 2 in ) 14 Popular Sizes 5 ft x 8 ft Use Location Indoor Feet) 400 Weight (lbs may also be used with non asphaltic systems such as slate wood metal Excellent walkability: special surface helps provide excellent walkability versus conventional felts or typical synthetic underlayments Stronger: non woven construction provides greater tear strength than standard #30 felt Lightweight: at approximately 16 lbs it's easier to load and handle on the roof than conventional felts Cooler to work with: light grey surface is cooler in hot weather than black felts UV resistant: resists UV degradation for up to 180 days