How to Install a Slate Tile Backsplash

Tiling a backsplash is very much like tiling over subfloor. Because backsplash areas are smaller in total square feet than flooring projects, there are a few differences and limitations that you should keep in mind. Using small tiles is easier in the long run than using large tiles. Using acrylic mastic instead of thinset saves mixing time and is easier to spread over drywall. And using a cement backer board product is not always necessary. When using slate tile to cover a backsplash, sealing the slate after the grout cures is a must.

Things You'll Need

• Cement backer board
• Backer board screws
• Penetrating grout and tile sealer
• Acrylic mastic
• Tiling trowel
• Tile spacers
• Grout
• Small bucket
• Grout float

Instructions

1. Test the drywall to be sure it is strong and structurally sound. Drywall that is soft or squishy, moldy, shows signs of dry rot or water damage, or is otherwise unfit to hold the weight of slate tile should be replaced. If you are applying slate tile that is 12 inches by 12 inches or larger, cement backer board should be applied to the wall prior to installing the tile. Cut the backer board to fit over the backsplash and fasten it to the wall by screwing it into the wall studs with backer board screws every six inches.

2. Apply one coat of high quality penetrating sealer over the slate tile before installing the tile. The sealer coat should be dry before the tile is installed.

3. Spread maximum strength acrylic mastic over the wall with a tiling trowel with teeth that are the appropriate size for the tile being used (see Tips).

4. Apply tile to the wall starting at the countertop and at the farthest point away from a wall corner. All cuts should be saved for corners where they can be somewhat hidden from view. Work in small areas at a time (2 foot by 2 foot). Use tile spacers between the countertop and the tile, and in between each wall tile to keep the grout lines straight, consistent, and even.

5. Allow the tile to dry on the wall at least 24 hours before grouting the tile. Mix a batch of grout in a small bucket with the right amount of water. The grout should be the consistency of peanut butter when it is ready.

6. Spread the grout over the surface of the slate tile with a grout float and force the grout into the grout lines. When the grout is in place, allow it to set up for 15 to 20 minutes. Wipe excess grout off the tile surfaces with a damp grout sponge, being careful not to disturb the grout in the grout lines. Use a corner of the grout sponge to smooth the surface of the grout to its finished quality. Allow the grout to dry and cure for 72 hours before applying two coats of penetrating sealer to the grout and the slate tile.

Tips & Warnings

• Use the following as a guideline for choosing the correct tile trowel for your slate backsplash project:

• 3/16 by 5/32 trowel for tile up to 6 by 6 inches

• 1/4 by 1/4 by 1/4 trowel for tile up to 12 by 12 inches

• 1/4 by 3/8 by 1/4 trowel for tile over 12 by 12 inches

References

• OmniGrip Maximum Strength Adhesive
• AcrylPro Tile Adhesive