What You'll Need:
- Black slate tiles
- Backboard
- Wet saw
- Tape measure
- Grout
- Black grout dye
- Thinset
- Trowel
- Sponge
- Plastic spacers
- Screws and power screwdriver
- Drywall mud
- Putty knife
- Sanding block
- Paint roller
- Grout float
- Caulking gun
- Caulk
- Metal edging strip
Step 1 – Install the Backboard
A backboard is the canvas in which black slate tiles will be placed. Backboard resembles drywall and consists of a concrete center and paper on one side. Measure the wall and then cut the backboard to size. Score the paper and then gently snap the board. Place the backboard on top of the plywood that is the main wall of the shower. Fasten it in place with screws at each corner. Place screws every 6 inches. Apply drywall mud over the screws using a putty knife and then smooth the mud out flat. When the mud is dry, sand it flat.
Step 2 – Place the Black Slate Tiles
Since walls are rarely uniform, you will have tiles that need to be cut. Measure down from the top of the wall a distance equal to the width of a full tile plus an additional 1/8-inch. Draw a horizontal line from one edge of the wall to the other. Repeat at the bottom but measuring up to draw the second horizontal line. Apply thinset to the wall between the lines using the straight edge of the trowel. Apply thinset to the back of the tiles and then set them in place one at a time using a spacer between each one. Continue placing black slate tiles until the wall is full. Apply thinset to the bare areas and add the full tiles. Measure the remaining space and then use the wet saw to cut the black slate tiles to size. Affix them to the remaining space.
Step 3 – Seal the Tiles
Black slate tiles are porous and need to be sealed. Wait a day for the thinset to dry and then paint the sealer over the black slate tiles. Wait a few hours for the sealer to dry.
Step 4 – Grouting
Mix the grout with the dye according to the directions and then apply it over the tiles with the grout float. The grout float evenly spreads out the grout while pushing it between the spaces. Use as much grout as needed. Wipe off the grout residue with a damp sponge to avoid a haze from forming over the tiles. The grout has to cure for several days before you use the shower.
Step 5 – Optional Finishing
If the black slate tiles are thick, you may want to add edging. Choose a metal strip that is as wide as the tiles are thick. Measure the top of the wall to where the wall stops and then cut the edging. Apply a bead of caulk to the edge of the tiles and then press the edging firmly in place. Remove excess caulk with a wet finger.
Source: www.DoItYourself.com