Things You'll Need
Grout sealant applicator brush
Masonry surfaces are low-maintenance compared to many other products. However, there are still processes required to care for installations like tile. One of these is to regularly apply masonry sealer. While some types of tile are available unfinished so that the entire surface can be sealed once they are installed, some tiles are already sealed and should not have sealant applied over the top. This may leave you wondering how to treat the grout between the tiles, which also needs protection. Though it requires some patience, there is a way to apply sealer only to your unsanded tile grout.
Clean the tiled surfaces very well following your normal routine. Once the grout is sealed it will maintain its color and appearance, sealing in any dirt or mildew. Let the tile and grout dry for a full day, since water may have been absorbed.
Remove all items from the room where the grout is. Cover anything that cannot be removed, including surfaces like countertops, with newspaper. Spread tarps over the floor to protect against spills.
Ventilate the room by opening windows and doors. Cover your hands and eyes in case you splash the sealer. If you are sealing floor grout, work from the farthest interior of the room toward the door so that you do not become trapped.
Dip a grout sealant applicator brush into the masonry sealer of your choice and apply it along the grout lines, working in one area at a time. Let the sealer sit for the amount of time recommended by your particular product and then wipe off excess product with a clean rag. Allow the sealer to dry for 48 hours before touching or walking on the surface or getting it wet.