IKO's RoofGard-Cool Grey surface provides a superior slip-resistant surface. Roofers can safely walk on it during dry installations. And since its grey instead of black, it absorbs less of the sun's radiant heat. This makes it much more comfortable for installers in hot weather, keeping the air temperature above the roof deck cooler. We have added lay lines every 1 inch to aid in shingle course alignment. Because the rolls are lighter and easier to handle than so many other underlayment's, RoofGard-Cool Grey is faster to install. RoofGard-Cool Grey is also lighter in weight.