Prep Coat Primer is a unique multipurpose 2 in 1 primer and waterproofing additive. Prep Coat Primer is used as a primer for Gripset Betta membranes to enhance adhesion to general surfaces. As a waterproofing admixture Prep Coat Primer will improve the water resistance and adhesion of cement based compounds such as mortars, slurries, grouts and cement based adhesives.