Chem Link. Suitable for use above or below grade, the Barr Liquid Waterproofing Membrane Repair Kit offers a handy solution for repairing small leaks on rooftops and around flashing. Applied by trowel or roller, the material cures to an elastic rubber and will not crack or slump in extreme temperatures, and the waterproof seal it creates will not shrink, the maker says. Eligible for a LEED point as a low-emitting material, the Barr Liquid Waterproofing kit contains the black, single-component membrane material and 25 square feet of reinforcement fabric. 800.826.1681.