Building a Shower Floor

Updating a bathroom is one of the most valuable home renovations that a homeowner can do. Whether replacing the entire shower stall or just updating it, this project needs proper planning and careful execution. If you are adding a new shower stall or replacing an old one, the first part that you need to install is the shower floor. For a new shower stall where there is no current footprint, you would need to find the ideal location not only for accessibility but for plumbing as well. If you don't have any experience with plumbing, it is highly advisable to hire a licensed professional to do the plumbing for you, which includes connections for the cold and hot water and drainage. For older shower stalls, use the existing plumbing. Start the demolition work to remove the old shower floor down to the subfloor, where you will install the new one. Avoid hitting the plumbing fixtures and pipes to avoid costly damages.


Drain unit on a shower floor.
Drain unit on a shower floor.

Gathering Materials

Ceramic tile.

Choose a flooring material for your shower that is long lasting and easy to care for. One good choice would be using a synthetic shower floor, which is a low-cost alternative and comes in one piece. You can choose slates and tiles. Choose the darker colored tiles and grout so that you do not have to worry too much about dirt buildup. Choose marble and granite slabs if you prefer a durable and low-maintenance shower flooring. Marbles and granites are quite pricey so think about your budget when considering these materials.

This example will show installation of a shower floor using ceramic tiles. Other materials to use are cement board or backer board, thinset or mortar, shower pan, trowel or float, grout, caulk, staples and drain unit. You would also need a saw for cutting the boards, a sharp cutter to cut the membrane liner, a tile cutter, staple gun and a caulk gun.


Build the shower base. Install the cement or backer board on the floor framing. Cut out a hole that can fit over the drainpipe where the drain unit would go. Apply a smooth layer of mortar or thinset using the trowel or float. Create a slight downward slope toward the drain to help prevent accumulation of water by helping it to drain away. Leave the mortar to cure overnight.

Apply the membrane liner on top of the cured mortar. Trim it and mold it into the shape of the shower base. Use staples to secure the membrane to the sides of the shower base. Cut a slit that would go over the drainpipe for the drain unit. Apply another layer of mortar on top of the membrane, which will become the base for the tiles. Let it cure for 8 to 10 hours.

Lay down your tiles starting from the center to allow for even distribution. Use the thinset or mortar adhesive. Use spacers to ensure that the spaces in between tiles are even. Use a tile cutter to trim down the size of tiles that would go to the sides. Leave an opening for the drain unit by trimming the tiles that surrounds the drain. Cut several pieces of tiles about 3 inches high that would go around the base of the wall connecting to the shower floor. Allow the tiles to set overnight.

The next day, apply the grout and wipe away any excess using a wet sponge. Let it set for 2 to 4 hours before applying another layer of grout to ensure full coverage. Remember to clean or wipe away any excess grout so that you will have a smooth finish. Allow the grout to cure overnight.

The next day, assemble the drain unit. Apply silicone caulk around the drain unit. Apply two coats of grout sealer to prevent mildew or dirt buildup. Let it dry for 4 to 6 hours before using.