Laticrete Waterproofing Membrane Fabric 6 in x 75 ft use for corners and coves Hydro Barrier Required for expansion gaps or cracks in surface S-09235-NF-19.. 26447. Waterproofing Membranes. A waterproofing membrane is a layer of water-tight material that is laid onto a surface to prevent water leaks or damage. Waterproofing.