Provides a physical barrier against mold and mildew growth on your grout. Penetrating sealer provides a long lasting physical barrier against stains from spills, water and oil on your grout. Use on all types of grouted tile surfaces. No need to clean offany residue from sealed tile after applying the grout sealer. No need to get on the floor to apply. Excess sealer evaporates away and does not leave any hard to remove residue on the tiles. Covers 500 linear feet.