Valcon Industries Flexcrete 5003 Polymer 5 gal, Waterproofing System is cement based and polymer modified to create a flexible waterproofing membrane. The Flexcrete Compound is a highly specialized blend of aggregates, cements, graded sands and proprietary additives. The material is to be used and mixed with Flexcrete Polymer as a waterproofing/overlay/micro topping material. Primary applications include concrete wall and block foundations, manholes and wastewater holding tanks, swimming pools & spas, reservoirs and potable water tanks, balconies, seawalls, and interior/exterior waterproofing all structures.