Krystol Mortar Admixture waterproofs and protects mortar rendering on brick, block, and other masonry walls. It reduces the permeability of plaster, stucco, and thin topping mixes and works with shotcrete and concrete overlayments. KMA incorporates the company's Krystol technology to eliminate the need for surface-applied waterproof coatings and membranes. It is a dry powder added directly to the mortar during mixing. Kryton International Inc. 800-267-8280.