- Stained grout
- Moisture working into the grout
- Mildew and mold growing within the grout
- Mildew and mold growing under the tile
Understand What Grout's AboutAfter you've laid down the tile in its bed of mortar and let it harden, it's time to grout it. Whether or not you do the actual tile job, understand how it is laid down:
Grout, either natural or colored, is smeared onto the tile and forced into the tile seams. It's like the glue that holds the tile edges together. And if you're using the aforementioned colored grout, it also adds to the beauty of the tile.
The "Where" of Tile Affects Its GroutTile can be used almost anywhere: kitchen, bathroom floor, kitchen backsplash, even inside the shower. Depending on the location, tile can get a little moisture, a moderate amount, or it can be absolutely deluged with moisture (in the case of a shower built with tile).
You've got to protect those grouted seams. Cement-based grout is porous, so it allows water to percolate inside (epoxy-based grout is different and is not covered in this article because it does not need sealing).
Sealing tile grout means that you apply grout sealer to the grout and let it infiltrate the porous structure—before the moisture can do this.
I cannot think of many tile installations that don't need grout sealing—perhaps a kitchen backsplash or any kind of tile that is purely decorative and never has contact with hands, feet, moisture, or anything.
Sealing Tile Grout Method #1: Follow the LinesThe surface of ceramic tile is glazed, meaning that it is already sealed. So what you need to do is buy a tile grout sealer that is applied only to the grout lines. It comes with an applicator and a brush, and the liquid looks milky. Crouch on your hands and knees. Got any gardening knee pads? Those help! Follow the lines with the applicator tip. Don't worry if you smear some on the surface of the tile; it will eventually come off.
It's painstaking work, but worth it. And if you're disappointed by the fact that you've finished the job, don't worry: you'll get to do it all over again next year. Yes, tile grout sealing should be done roughly once a year.
Sealing Tile Grout Method #2: Spray OnA second method of sealing tile grout involves spraying the entire tile surface (as long as the surface is glazed). The theory is that the grout sealer penetrates the porous grout, as it should, yet lays atop the glazed tile surface. Then, the sealer on the glazed tile partially evaporates and partially wears off after usage.
Reviews of spray on grout sealant are mixed. Some homeowners say that this spray-on sealant doesn't percolate into the grout as well as the brush-on stuff. Also, there are some reports of this sealant damaging the tile caulk—not a good thing.