· by Michael Blair, Nashville's Tile and Stone
Sealing is sold as a blanket service and only some materials need it. Knowing which saves both money and effort.
Which tile and grout need sealing?
Cement-based grout, which is porous and stains. Natural stone tile — marble, travertine, limestone, slate — which absorbs.
Epoxy grout does not need sealing, because it is not porous. Nor does porcelain or glazed ceramic tile.
What does not need sealing?
Porcelain and glazed ceramic have a vitrified surface that absorbs essentially nothing. Sealing them puts a film on the surface that wears unevenly and looks worse.
A company offering to seal your porcelain floor is selling something that does nothing.
- Cement grout: seal, and reseal periodically
- Natural stone: seal, using a stone-appropriate product
- Porcelain and glazed ceramic: do not seal
- Epoxy grout: no sealing needed
- Test with water rather than following a schedule
How often
By condition rather than calendar. Drop water on the grout — if it darkens, it is absorbing and needs sealing; if it beads, it does not.
A shower floor needs it far more often than a bathroom wall, because of the volume of water it sees.
Application
The surface must be genuinely clean and dry first, or you seal the dirt in. On a floor, a penetrating sealer applied and the excess wiped promptly gives the best result.
Excess left to dry on the tile surface leaves a haze that is tedious to remove.
FAQ
Sealing Tile and Grout, and What Needs It — questions
Do I need to seal porcelain tile?
No. Porcelain is vitrified and absorbs essentially nothing, so a sealer sits on the surface, wears unevenly and eventually looks worse than bare tile. Only the cement grout between the tiles benefits from sealing, along with any natural stone.
How often should grout be resealed?
By condition rather than schedule. Drop water on it and watch — if it darkens the grout, it is absorbing and needs resealing; if it beads, the seal is intact. A shower floor typically needs it far more often than a wall or a floor away from water.
Is epoxy grout worth the extra cost?
In a shower or a busy kitchen, often yes — it is non-porous, does not stain and never needs sealing. It is harder to work with and more expensive to install, and installers charge accordingly. In low-traffic dry areas, sealed cement grout is perfectly adequate.
How do you seal grout?
Clean the grout thoroughly and let it dry completely, or the sealer locks the dirt in. Apply a penetrating sealer to the joints and wipe the excess off the tile promptly, because sealer left to dry on the face leaves a haze that is tedious to remove. Afterward, a drop of water should bead on the grout.