Crystalline waterproofing admixture reacts with calcium hydroxide and other by-products of cement hydration to produce a non-soluble crystalline formation that fills and plugs the capillary pores and micro-cracks in concrete, blocking the entrance of water and soluble chemicals. XYPEX admixture replaces coating products in most applications, such as foundations, tunnels, septic tanks, manholes, sewer pipes. XYPEX Chemical Corp.