Ceramic tile does need occasional maintenance, to replace broken tiles or to regrout the joints between the tiles. Before tackling a fix-it job, however, assess any underlying problems. If you find any of the following, you may be dealing with adhesive that's failing, a floor surface under the tile that's not level or that's flexing too much, or water that's seeping under the tiles and into the flooring. You'll likely need to replace the tiles, and possibly the subflooring.
Many tiles are loose or cracked.
The grout is deteriorating over the whole area.
The floor feels spongy when it's pressed.
The tiles have a cloudy discoloring.
Replacing a Broken Tile
First, you need to remove the damaged tile. Use a grout knife (a jagged metal blade in a holder) to carve out the grout around the tile, being careful not to scratch the surrounding tiles. Save some of the old grout chips to make it easier to buy the right color replacement grout.
You may be able to pry the damaged tile up off the floor by inserting a small pry bar or cold chisel under it and tapping the bar or chisel with a hammer. If not, strike the tile at its center, breaking it into pieces that should then come off more easily. Scrape off any old tile adhesive or loose grout to provide a smooth surface.
Spread tile adhesive onto the back of the new tile with a notched trowel. Press the new tile into place, centering it in the gap. If it's not sitting down far enough, lay a piece of carpet or foam over it, and tap it into place with a block of wood. Hold it in place with masking tape or tile spacers. Clean out any adhesive that has seeped into the joint around the tile. When the adhesive is dry, grout around the tile (as described in the next section).
Ceramic tiles can last a long time-longer, in fact, than the grout around them, which can crumble or become discolored. Eventually, you'll need to regrout the tiles, which is a job that will take at least a day, and probably a weekend, for a typical bathroom floor. (Before you start, check that the ceramic tiles and the wall behind them are in good shape.)
Grout is a powder made of cement and pigments and comes in a variety of colors. Floor grout usually contains sand, while wall grout generally doesn't, although you'll also find all-purpose grouts. When mixed with water or a grout additive, the powder becomes a strong and flexible joint filler. (Using grout additives can improve grout performance and color retention.)
Start by removing any silicone caulking in the area to be regrouted and raking out the old grout from the joints with a grout knife. Use a stiff brush or vacuum to clean out any loose pieces or dust, giving you a clean surface to work on.
Add the grout powder to the water or additive, as per your grout's instructions. Apply grout to the tiles with a rubber-bottom float, packing it into the joints. Work diagonally across the tiles, in a figure-eight motion, to avoid pulling grout out of the joints you've just filled.
Wear gloves during this fix-it job, first to protect your hands when you're chipping out the old grout (tile edges can be sharp), and t to protect your hands from the new grout, which can be caustic.
Remove excess grout by holding the float at a right angle to the tiles and running it diagonally across the joints; then use a water-dampened sponge to clean any remaining grout off the tile surfaces, always moving diagonally (work on an area about 2 feet square at a time). Rinse the sponge after each pass to ensure that as little grout as possible remains on tiles. (If you use a grout cleanup solution instead of water, you may need to allow the grout to set in the joints before doing this. Check the package instructions for suggested times.)
Level out the grout in the joints by pressing the joints lightly with a damp sponge. Any remaining grout haze that forms on the tiles can be wiped away the following day. Let the grout cure according to package directions (usually twenty-four to forty-eight hours).
Once the grout is cured, run a bead of silicone caulking in the space wherever the tiles meet another material, such as a bathtub (fill the bathtub with water first, to help prevent the caulk from cracking). Smooth the bead out with a moistened caulking tool, curved spoon, or sponge, and allow it to cure.
Regrouting ceramic tiles is messy, and it can be time consuming-but the end result is a clean new finish for your tiles, and it's a lot faster than replacing the tiles themselves.
Grout will last longer if it's sealed against water and dirt. You can buy grout sealer at home centers-just follow the instructions on your product. In general, you'll first clean the grout and the tiles (if you've just regrouted the seams, you'll need to let the grout cure for at least three weeks before sealing). Paint the sealer onto the grout seams, trying to avoid getting too much on the tiles themselves, unless your product is designed to seal tiles as well. You may need to apply two to three coats. Let the sealer dry as per your product instructions. You can expect to reseal the grout every year or SO, depending on how much use or water splashes the area receives.