How to Redo a Shower Floor
A shower floor that holds water or contains sharp-edged tile cuts needs its tile and the top layer of its mortar bed redone. Many shower tile installers fail to float the floor's base properly, leaving the low spots in the mortar mix that form puddles. A shower floor's slope falls toward the floor drain at about 1/4-inch per foot. Soap residue and hard-water stains often soak into a poorly constructed shower floor's tile grout, giving the grout an orange or gray hue.
Cover the shower floor drain's cover with masking tape. The masking tape prevents debris from falling into the floor drain while redoing the shower floor.
Cut out the caulking around the perimeter of the shower using a utility knife. The caulking traps moisture in the grout cracks next to the wall and promotes mold and mildew growth.
Grind the grout from the seam between the floor tile and the floor drain, using a grout saw. A grout saw uses a carbide blade to cut the grout.
Place a cold chisel's blade on any grout joint on the shower floor. Strike the chisel's handle with a hammer until the tile next to the grout joint breaks free. A white-colored mortar, called thinset, holds the shower floor tile to the shower's gray-colored mortar base.
Wedge the chisel's blade between the floor tile and the thinset, using the hammer to push the chisel. Remove all of the shower floor tiles using the hammer and chisel.
Place all of the old shower tiles in a bucket. Discard the tile debris.
Hold a brick on the thinset covering the shower floor's mortar base. Press down on the brick and work the brick back and forth across the thinset, smoothing its top layer. Remove any high spots in the shower floor with the brick.
Clean the debris from the shower floor using a vacuum to remove the dust from the thinset's pores.
Dampen the thinset covering the shower floor's mortar base with water. The thinset's color changes from bright white to a light gray color as the water soaks into the mortar.
Sprinkle an 1/8 to 1/4-inch-thick layer of powdered thinset onto the damp shower floor. Hold the edge of an 18-inch flat trowel on the powdered thinset and smooth the thinset's surface with the trowel's edge. Let the moisture from the shower base soak into the powdered thinset before continuing.
Set sheets of shower floor tile onto the thinset covering the shower floor's base, using a tile cutter to trim the tile as needed. Do not press the tile into the wet thinset.
Tamp the new shower floor tile into the wet thinset with a grout float, working from the floor drain toward the shower walls. Hold a bubble level on the wet tile. Press down on the high tiles with the grout float, using the bubble level a a guide. Continue to work the floor until it has an even and smooth slope, using the grout float to adjust the tile's position.
Clean the excess thinset from the shower floor's grout joints with a sponge. Let the thinset dry before continuing.
Combine the shower floor's grout and water in a bucket, using the grout manufacturer's instructions. Push the grout to the bottom of the new shower tile's grout joints, using the grout float to spread the grout. Wash the excess grout from the shower floor with the sponge.
Things You Will Need
- Masking tape
- Utility knife
- Grout saw
- Cold chisel
- Thinset mortar
- 18-inch flat trowel
- Shower floor tile
- Tile cutter
- Grout float
- Bubble level