Products / Gardner Gard-Lock Roof Underlayment

Gard-Lock is a self-adhered, fiberglass-reinforced asphalt membrane underlayment with a mineral-surfaced, non-skid top and a release liner, for use under asphalt shingles, wood shakes, slate and tile to guard against leaks from ice damming and wind-driven rain. It is sold as product GG-4100-15, a 36-inch by 50-foot roll covering 1.5 squares. Its technical data sheet lists properties tested under ASTM D1970, a moisture vapor permeability of 0.05 perms (ASTM E96), and compliance with ASTM D1970, AC48 and the Florida Building Code, and calls for an ASTM D41 asphalt primer where priming is wanted. The data sheet warrants satisfactory results for 12 months from purchase when directions are followed.