IB-3 is an economical waterproofing underlayment featuring a granulated surface that keeps ice dams, melting snow and blowing rain from entering the structure. The self-adhesive backing forms a strong bond to the roof deck, and the tough, rubberized asphalt seal-seals around nails and fasteners. Applies easily at eaves, valleys, vents, skylights and chimneys. The release film has a centered perforation that makes for a very easy installation in valley areas. A rugged and time tested product in cold, rainy climates where ice dams can quickly occur. Installs in temperatures above 40 degree F. 5 year warranty, 30 day exposure.