Best Products And Procedures For Sealing A Slate Tile Floor

Slate Tile Sealing Tips

By Troy Cantini

Slate tiles are very porous types of tiles and they should definitely be sealed.  Since slates tiles can naturally look kind of drab, dull and lifeless. There are various sealing solutions designed to seal the slate tiles and also enhance the color and sheen of the slate. There are various topical glossy, matte and enhancing sealer options available for sealing slate floor tiles.

black slate tiles with glossy sealer

  • Impregnating clear sealers.

  • Enhancing sealers.

  • Topical glossy sealers.

All of these sealers have their distinct advantages and disadvantages for sealing slate.  You should choose a sealing option that best suits your slate for depending on how you want the floor to look and how much maintenance is required for the sealer chosen.

There should be no color change or change in the glossiness of the slate tiles and grout after the tiles have been sealed.  After the sealer has dried you should be able to apply some water drops to the tiles and grout and see that the water beads up a lot more now that the sealer has been applied. Slate tiles are extremely porous so it may take a couple of coats of sealer to provide adequate protection for the slate.

Water based impregnating sealers usually work better than solvent based sealers for cleaning slate. The porous nature of slate requires that the sealer have a bigger molecular structure provided with a water based sealer. Solvent based impregnating sealers can also be used but you may be required to apply more coats of sealer till the slate tiles are completely saturated with sealer.

To seal the slate tiles with an impregnating sealer just pour the sealer directly on the slate and use a cotton towel to spread it around on the slate. Allow about 5-10 minutes for the sealer to be completely absorbed by the slate. You will probably have to keep applying sealer to the porous slate to keep it saturated for the entire 5-10 minutes. Then you can simply wipe the excess sealer off the slate tiles and grout. Be sure not to allow any excess sealer to pool up on the tiles or grout when you are done. You should see the tile and grout darken up when the sealer is applied but after the sealer dries you will see the slate tiles and grout return to their original non sealed appearance.


An enhancing sealer is almost the same as a solvent based impregnating sealer except that the sealer will also enhance the colors and sheen of the slate.  Slate in its natural state can be dull, drab and lifeless and an enhancing sealer will brighten up the slate and enhance the colors of the slate tiles. Additionally an enhancing type impregnating clear sealer will also add small level of glossiness to the slate tiles.

If you want to further enhance the slate and add even more glossiness you can add a second coat of the enhancing sealer.  It is not recommended to apply more then two coats of enhancing sealer to the slate. You apply the enhancing impregnating sealer exactly the same as the impregnating clear sealer. You should test the enhancing sealer on a spare tile to see if you like the look of the enhancing sealer before you apply the enhancing sealer to your slate tile and grout.

A topical glossy sealer will add the ultimate glossy finish to your slate surface.  Topical glossy sealers come in solvent based and water based formulas. Solvent based topical sealers are more durable but can have harsh fumes when applying the sealer. Solvent based topical sealers can also be extremely difficult to strip and remove if the sealer ever needs to be stripped and removed. Water based topical sealers for slate have almost no fumes and a respirator is not needed when applying water based topical sealers to slate. Both types of topical glossy sealers will take away all of the chalky appearance of the natural slate surface. This type of finish can add the marvelously beautiful luster to your slate surface that many people have come to love. Additionally the topical sealer will make it impossible for any types of contaminates and stains to enter the slate tile surface.

water based topical sealer for slate

Topical glossy sealers do come with a price though.  The glossy tile surface will over time scuff up and lose its glossy appearance. Additionally dirt, grit and grime can become embedded in the topical sealer surface. Therefore every couple of years or so depending on the frequency of use the slate tile and grout will have to be stripped and resealed. Water based topical sealers will be easier to strip and redo than solvent based topical sealers.

water based topical sealer for slate

Applying a glossy sealer to slate tiles and grout can be a tricky procedure.  Ensure that only a light coat of sealer is applied to the tile surface and there are no puddles of sealer left in the grout. After you apply the sealer to one area move on and do not attempt to go back and redo any areas that have already been done. It should only take about an hour total for the topical glossy sealer to dry on the slate surface. If done properly you should see a beautiful glossy finish on the slate surface.

If more glossiness is desired you can apply a second coat of sealer to increase the shine on the slate tiles.  Make sure that the first coat of sealer is totally dry before applying a second coat of sealer. A professional tile restoration company may be able to apply a second coat of sealer immediately after the first coat of sealer. On the other hand most do it yourself homeowners should wait at least a few hours before applying a second coat of glossy sealer.

No matter what type of sealer you apply to your slat tile and grout you should maintain the finish by keeping the slate clean with a pH neutral tile and stone cleaner.  The pH neutral formula will clean the slate tile and grout without breaking down or dulling the finish of the sealer. Frequent cleaning with clean mop water using the ph neutral cleaner will help to maintain the beautiful look of the slate tile surface. .

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