DESCRIPTION Krystol Waterstop Grout™ is a specially formulated powder containing the proven chemistry of Krystol™ integral crystalline waterproofing. Krystol Waterstop Grout is a primary component of the Krystol Waterstop System™ and is used to create concrete construction joints that are permanently waterproof. In order to produce a crack-resisting and durable grout, the internal red powder contains polypropylene (PP) fiber. The active ingredients in Krystol Waterstop Grout combine chemically with water and concrete to form millions of needle-shaped crystals that grow in all directions to fill any capillary pores, cracks and joints that might otherwise allow water to pass.