Viper Grout & Concrete Sealer from Hydro-Force utilizes a unique new formula to achieve the benefits of solvent-based grout sealers in a water-based product. As any good impregnating sealer should, it resists soils, stains and chemical degradation, offering excellent oil and water repellency. Grout & Concrete Sealer is vapor permeable so it lets water vapor out but doesn''t let liquid water in. Viper''s formula carries none of the health or safety concerns associated with solvent-based products. Effective on grout, this product can also be used on any porous tile such as quarry or Saltillo as well as concrete.