Rubberized asphalt layer seals around fasteners Resists water leakage Superior adhesion to the deck Water-tight laps formed from membrane Ripcord split release on-demand makes for easy application Slip-resistant surface Reroofable; will not attach to the underside of exposed roof covering Covered by CertainTeed's SureStart Warranty Roll Thickness: 40 mils Tensile Strength: 250 psi UV Exposure: 120 days Can be applied over the old GCP underlayment The Grace Self Adhering Ice and Water Shield is a self-adhered, peel-and-stick substrate made of aggressive, rubberized asphalt adhesive. This roof underlayment is designed to protect under slate, tile, cedar shakes, metal roofing, or beneath conventional asphalt shingles. This adhesive is backed by a cross-laminated, high-density, and coated polyethylene film for slip resistance.