Tarco Leak Barrier is a glass fiber reinforced, self-adhesive roofing underlayment for use under slate and asphalt shingles. Mineral granules on the upper surface provide enhanced skid-resistant properties. Tarco Leak Barrier helps to protect a building's deck or internal structure against leaks caused by ice and water damming and wind-driven rain. It's highly effective in critical roofing areas such as valleys, ridges, coping joints, chimneys, vents, dormers, skylights, and low-slope sections.