We recommend waiting for at least 48 hours after installing a grout before you apply a sealer. Older grout should be cleaned thoroughly before being left to dry. Make sure to protect grout from spills and stains during this time, otherwise you'll be sealing in the dirt instead of keeping it out!
Even if you get impatient, you must wait for the grout to completely dry before applying the sealant. If it is applied to damp grout, the sealant will end up peeling off and leave the grout exposed to dust and dirt.
You can seal the grout the day after you applied it or 100 years later. If it isn't dirty, seal all three sides of the shower with a tile sealer or masonry sealer. That will make the grout water-resistant, if not waterproof, and help prevent the growth of mold and dirt.
Grout needs to be sealed. It's naturally porous and will stain easily. Most installers of tile floors do not seal them because grout has to cure first. It's something you should do to keep your grout looking its best.
After you've installed new tile, you want to wait at least 48 to 72 hours for the grout to dry and cure. Your grout should be clean and dry and make sure the grout lines are cracked or chipped. If they are, then touch up the grout and then wait an additional 48 to 72 hours before you start sealing the grout.
We recommend waiting for at least 48 hours after installing a grout before you apply a sealer. Older grout should be cleaned thoroughly before being left to dry. Make sure to protect grout from spills and stains during this time, otherwise you'll be sealing in the dirt instead of keeping it out!
Grout almost always appears darker when wet than when dry. New grout can take 24 or even 48 hours before it dries completely. It depends on the humidity and temperature in the room where the grout is installed.
Be sure to let your grout sealer dry thoroughly before testing a small area with a few drops of water. If the water beads up, you're all set! If not, you'll need to apply an additional coat of sealer to your grout. Most grout sealers take 1-3 coats for best results.
Signs Your Grout Isn't Sealed or the Seal Is Deteriorating
If you notice your tile grout is changing color, specifically getting darker when it's wet, you can be pretty sure the seal is broken and needs to have some grout sealing reapplied by a professional.
MAPEI offers Penetrating Plus Stone, Tile & Grout Sealer which is a water-based sealer and Penetrating Plus SB Stone & Porcelain Tile Sealer a solvent-based sealer. Let's be clear, sealing does not make grout stain or waterproof.
Sponging the grout too soon will pull it out of the joints, so let it set for about 15 minutes. After that, use a damp sponge to clean the face of the tiles in a light, circular motion. Next, clean the sponge and go over the tile again, wiping at a slight diagonal to the joint.
After making sure that your tiles are freshly installed and grouted, then it's time for sealing grout! Once you make sure your grout lines are clean without any cracks or chips, give it at least 48-72 hours to ensure it's completely dry and cure before applying the sealer.
You want to get your tile and grout really really clean before you seal it. If you seal dirty tile, it will forever remain dirty! So, cleaning it thoroughly is a must.
Let dry for at least 8 hours
Finally let the shower wall or floor grout to dry for a minimum of 8 hours before getting this area wet and using the bathroom again.
Assess the Grout
Another way to check if the grout has been sealed is to monitor the water beads. If the water beads flow done from the ground, it is correctly sealed. However, if the grout absorbs the water, either the grout hasn't been sealed or the sealer has worn off.
The only type of grout that doesn't need sealer is epoxy, which is inherently pre-sealed. Grout sealers typically come in two forms-- spray-on sealers and applicator sealers. Applicator sealers are applied directly to the grout with a roller ball or a brush.
But does grout color really change when sealed? In short, the color doesn't change after sealing. But you can expect the shade to darken a bit. And don't worry; it's not a drastic change.
Grout almost always appears darker when wet than when dry.
Floor grout, in general, usually dries completely after 24 hours, although humidity and other factors can extend this drying time to 48+ hours. Grout haze can sometimes be simply buffed out with a dry towel or cheesecloth, if done immediately within the first 48 hours.
There is no reason not to wait to apply grout, unless you have used a quick-set tile adhesive. The thin-set mortar needs time and air to properly set and cure for strong bonding. Improper curing can lead to a flaky adhesive, which will cause loose or failing tiles and bonds.
Once the grout is cleaned, you do want to seal it to protect it from dirt, mold, bacteria and mildew. Buy a high-quality, professional-grade sealer and read the directions carefully before starting applications.
Before you clean the grout between your tiles, it's always a good idea to clean the tiles first. If the tiles are on your floor then give them a good mop. If the tiles are on the walls then wipe them down with a moist cloth and a cleaning solution; all purpose kitchen or bathroom cleaner will do.