WIP 250 is a self-adhering composite underlayment that consists of fiberglass-reinforced rubberized asphalt laminated to an impermeable film layer to provide dual-barrier moisture protection. Withstanding temperatures of up to 250 °F (121 °C), it is an ideal product for use under metal and mechanically fastened tile roofs and provides unsurpassed protection from water penetration caused by wind-driven rain and ice dams.