How to Do a Shower Floor
by Robert Ferguson
A shower floor must include a pitch for proper drainage.
One of the last steps for a shower remodel is to install the shower floor. Typical shower installation involves installing the shower liner, cement board and wall tile before floor installation. It is critical that you install the shower floor correctly to avoid circumstances that could ruin the outcome of your project. Often, homeowners who attempt this project fail to recognize the importance of tapering the floor to allow for water drainage. A shower floor that holds water allows mineral deposits, dirt and other debris to form on the surface. Professional tile setters save time and money by using this process to install the sub-floor and shower floor tile in one trip.
Tools and Supplies
Before beginning this project, you should gather the necessary tools and supplies to complete the job. Mixing the mud for the shower sub-floor requires Portland cement, builder’s sand, 5-gallon buckets, a square-point shovel and water. Setting the shower floor requires a trowel, a 2-foot level and a small torpedo level. Setting the shower floor tile requires un-sanded thinset, a 4-inch wooden block, a tile cutter, tile nippers and a sponge.
Mixing the Shower Floor Mud
Mixing the shower floor mud requires an open area of concrete such as a driveway. A common sized shower requires approximately five to six buckets of mud mixture. It is better to make too much mud than not enough. The mixing ratio is 40 pounds of Portland cement to five buckets of builder’s sand. The sand and cement are first mixed together dry by placing the materials in a single pile on the concrete surface and mixing with the shovel. After mixing them thoroughly, sprinkle water over the mixture using a sponge and continue mixing until it has the consistency of brown sugar.
Setting the Shower Floor Mud
The shower drain must be set to its proper level before placing the shower floor mud, usually about 1 1/2 to 2 inches from the sub-floor is sufficient. Use a 5-gallon bucket to transfer the mud mixture into the shower floor area and spread evenly throughout. Since the bottom of the first row of wall tile is usually about 3 to 4 inches from the bottom of the shower floor, and the drain is 2 inches above the shower floor, the area around the drain will requires less material.
Creating the Shower Floor Pitch
Once the shower floor mud is in place, to allow for proper water drainage, use the trowel to tap, compact and taper the entire surface of the shower floor. Add mud as needed to ensure that the floor surface is even with the bottom edge of the first row of wall tile and the bottom edge of the shower drain. Once the mud is compacted, it should be shaped or tapered using the trowel to ensure that it drains properly and does not contain low spots that would allow water to pool. Placing one end of a level on the top of the drain with the other end extended towards the outer wall is a sufficient way to identify the floor’s pitch and to address any low spots.
Installing the Shower Floor Tile
This method of shower floor installation requires that the shower floor tile be set immediately following sub-floor installation. First, sprinkle a 1/4-inch layer of un-sanded thinset over the entire surface of the shower floor mud. The un-sanded thinset binds the shower floor tile to the sub-floor. Lay out the pattern of your floor tile, while keeping the drain in mind. A shower floor incorporating the largest pieces of tile possible around the drain is ideal for comfort purposes. Place the tile on the surface of the shower floor and firmly press into place. Continue this process for the remaining tiles while making any required cuts along the way using the tile cutter and nippers as you go.