How to Tile a Shower Over a Concrete Slab

Slide the bottom flange of the drain pipe assembly into the drain hole on the concrete slab.

Mix a batch of mortar, following the instructions on the packaging, then spread the mortar over the concrete inside the shower stall. When applying the mortar, add about 2 more inches around the edges of the shower to make it easier to create a slope that leads to the drain.

Smooth the surface of the mortar with a 2-by-4 board, sloping the mortar toward the drain so that it's about 1 1/2 inches lower around the drain than around the perimeter of the shower. Let the mortar set for four to five days.

Snap a chalk line across the middle of the shower floor between two of the walls, then snap a second chalk line between the other two walls to divide the floor into four even quadrants.

Mix thinset mortar for the floor, following the manufacturer's instructions.

Spread the thinset onto the shower floor with the smooth edge of a notched trowel. Begin in the corner of one of the quadrants where they intersect in the center of the floor. Cover an area of the floor that measures 1 square foot, then create grooves in the surface of the thinset by running the notched edge over the mortar.

Lay the first tile into the thinset at the corner where the four chalk lines intersect in the center of the floor. Place tile spacers around the tile, then lay the next tile, working toward the side wall. Continue to lay thinset, tiles and tile spacers until you reach the wall or cannot fit a full-sized tile onto the floor.

Lay a second row of tiles in the same quadrant that run perpendicular to the tiles in the first row. After these rows have been laid, they will resemble the letter "L." Continue to lay alternating rows of tiles until the quadrant is complete.

Lay tiles in the other three quadrants, using the same method. Tile around the drain hole by holding the tiles in place around the drain hole, and tracing the edge of the drain hole onto the tile. Cut the tile with a wet saw, then install it with the thinset.

Cut tiles to fit around the outer edge of the shower, and place them into thinset on the shower floor. Let the thinset set for about an hour.

Take the tile spacers out of the joints between the tiles with a pair of needle-nose pliers, and remove any thinset from the surface of the tiles by scraping it off with a putty knife. Take care not to scratch the tiles when doing this.

Mix a batch of grout, following the instructions on the packaging, and place two scoops onto the floor in one corner with a grout float. Spread the grout onto the floor by diagonally sliding it over the tiles. Make several passes in the same area so the joints are completely filled with the grout before moving on to the next section. Let the grout set for 20 to 30 minutes.

Wipe off the surface of the tiles with a damp sponge, rinsing it often. Let the floor set for 45 minutes.

Wipe the hazy film off of the surface of the tiles with paper towels.