Use small shims or other spacers to allow a small amount of space between the bottom of the marble tile and the lip of the shower pan. Small pieces of cardboard work great as makeshift shims. After the mortar is set, you can simply remove these shims and caulk between the lip of the pan and the bottom of the wood tile.

Continue laying the tile, making sure to use spacers in between tiles. Spacers will leave you identifiable grout lines between wood tiles. Small 1/16″ or 1/8″ spacers (or even bigger) can be placed at several places on the x- and y-axis of the wood marble tile to leave adequate space for an even grout line.

Repeat the procedure, setting each row of tile on top of the last row of wall marble tile. Continue until you reach the top of the shower stall. Measure up from top of the last row. Mark the line with a level as a guide for your next row. Spread thin-set onto your tiles design with v-notched trowel and place the tile just below the marked line. Use spacers all around. Make sure to measure every third or fourth row to ensure that you have an even grout line. Let the tile set for 48 hours. This will make sure that the mortar has adhered properly to both the rustic tile backing and the cement board backer.

Don’t cut any partial pieces yet. Set aside all of the pieces you’ll need to cut partial pieces. After placing full pieces on your wall, you may find that the size of the partial pieces you’ll need is a little different than what you anticipated.

Place a cloth or plastic cover over your countertops and appliances. Use a cloth or plastic to cover anything you want to protect from adhesive, grout, and caulk. Most importantly, place cloth or plastic over your counter tops, on appliances, and on any furniture in the immediate area. Secure drop clothes to countertops and appliances with painter’s tape.

Cover the edges of cabinets and appliances with painter’s tape. Take the time to systematically cover the edges of cabinets, appliances, and woodwork. This way, you’ll protect cabinets and more from being stained with grout or caulk.

Rub 80-grit sandpaper back and forth on the area you are tiling. When your sandpaper wears out and isn’t as abrasive, use a fresh piece. Make sure you sand the entire surface that you are tiling. Sanding will make it easier for the spots tile to adhere to the wall.