Sika® Watertight Concrete Powder is a combined water resisting and HRWR/Superplasticizing admixture used to enhance the workability and reduce the water permeability of concrete. When added to concrete, the HRWR component in the admixture allows for the reduction in the water-cementitious ratio and reduces the large capillary pores in the concrete – the pore blocking component blocks the remaining small capillary pores by forming a hydrophobic layer within the pores. Sika® Watertight Concrete Powder meets requirements of ASTM C 494 Type F, ASTM C 494 Type S and is ANSI/NSF 61 certified and in ANSI.