RIW Cementseal is a two component polymer modified cement based waterproof concrete sealer coating with excellent adhesion to prepared concrete and masonry substrates. When mixed, this concrete and masonry sealer exhibits a good degree of thixotropy to enable ease of application by brush or spray techniques to give an even finish with no sagging even in vertical situations. It cures to form a durable, highly alkaline, tough waterproof coating which acts as a concrete waterproofing sealer and protects the concrete, or other substrates, from water penetration and carbon dioxide diffusion. It can also be used as a concrete floor sealer.