How to Build a Shower Enclosure
You need to build a wall—sometimes two—to install a new shower. Here's how to do it.
Adding a new shower can be a lot of work. After all, a new corner shower stall requires building one wall. A new shower placed in the middle of a wall requires building two new walls. Plus, if the walls do not go to the ceiling, the top ledge must be covered with tile or another moisture-resistant surface. The opening can have a door or a curtain rod.
That being said, a new shower can transform your bathroom space. You'll have more room and privacy. A one-piece unit is the simplest shower to install, though you have a limited choice of colors. Buy a base that's at least 34 inches wide. Some bases must be set in thinset mortar or in a bed of sand, while others can simply be placed on the floor. Before you begin, prep the space by installing a drainpipe with trap in the center of the base, as well as supply pipes, faucet, and a shower riser. The flange should be level with the floor. Run the supply pipes after the framing is installed. Also make sure you're comfortable working with plastic and copper pipe, framing a wall, and installing tile.
What You Need
- Carpentry tools
- Tools for plastic and copper pipe
- Tiling tools
- Steel rod
- Shower base
- PVC primer and cement
- Roofing felt
- 2x4 studs
- Cement backerboard
- Backerboard screws
- Tile adhesive
- Shower door
Installing the Shower Base
Step 1: Install Drain Extension
Set the shower base over the drain to make sure the drain is directly below the opening of the base. Remove the base and cut and cement an extension to the drainpipe. The extension should be flush with the floor.
Step 2: Level it Out
Place a layer or two of roofing felt to smooth any unevenness in the floor. (Some manufacturers require a bed of mortar or sand.) Set the shower base over the drain to confirm that the drain is positioned correctly. Check for level; shim with additional roofing felt as needed.
Step 3: Fit Rubber Flange
Using liquid soap as a lubricant, fit the rubber flange (provided with the shower base) over the drain extension and push it as far down as you can. Tap it all the way in place with a 1/4-inch steel rod. Install the drain strainer.
Editor's Tip: If the base uses a PVC flange, cement the drain flange to the drainpipe; the flange should be flush with the floor. Set the gaskets on top of the flange. Place the shower base over the drain hole. Check that the gaskets are still in place. Screw the drain body through the hole in the base and into the flange. Attach the strainer.
Framing the Shower
Step 1: Build Wall Sides
With the shower base in place, build 2x4 walls for the sides. Remember that the studs will be covered with 1/2-inch-thick cement board, plus the tiles (usually about 3/8 inch thick). No studs should be farther apart than 16 inches. On the plumbing wall, space the studs so you can position the shower faucet—a pair of studs spaced about a foot apart will accommodate most faucets. Install horizontal braces to support both the faucet and the showerhead arm. Some bases may require a ledger. Install the supply pipes and faucet.
Step 2: Install Backerboard
Cut pieces of cement backerboard to fit. Cover all wood surfaces with the backerboard. Attach to the studs with backerboard screws. Check that the wall surface is smooth and even because the tiles will follow any contours. Before tiling, caulk the gap at the bottom.
The bottom of a wall, where the tiles meet the shower base, must be installed correctly, or water will seep behind the tiles and damage the studs. Install the backerboard all the way to the top of the base's flange and fill the gap below with caulk. Apply tiles and a bead of caulk.
Step 3: Tile the Wall
Cover the backerboard with ceramic tile or with a prefab tub surround kit. Consult a book on tiling for guidelines on selecting, laying out, and cutting tile. In general, tiling should be planned to minimize small pieces. Wherever a tile edge will be exposed, install a bullnose piece, which has one finished edge. Use a notched trowel to apply thinset mortar or organic tile adhesive and set the tiles. Use a tile-cutting hole saw for the faucet and showerhead stub outs. Once all the tiles are applied, allow the adhesive to set overnight.
Step 4: Grout and Caulk
Mix a batch of latex-reinforced grout and use a grout float to push the grout into the joints and scrape away most of the excess. Wipe several times with a damp sponge, working to create consistent grout lines. Allow to dry, and buff with a dry towel. Caulk all the inside corners.
Install the Shower Door
Measure the opening and select a door with a frame you can adjust to fit your unit. Follow manufacturer's instructions. In general you'll begin by cutting the jamb piece to size and installing a bottom track and seal. Each jamb is made of two interlocking pieces. One attaches to the stall with screws and anchors. When both jambs are installed, decide which way the door should swing and install the hinged insert with the clamps provided. Slide the door in place, cap, and add the door handle. Install the other jamb insert and adjust.
Bonus: Understanding One-Piece Shower Units
Corner and rectangular shower stalls—made of acrylic fiberglass or polystyrene—are much easier to install than a custom-made enclosure. One-piece units are designed for new construction only because they are too large to fit through a door. Three-piece units are quickly assembled and are ideal for remodeling.
The walls of these units must be installed against solid walls. A corner unit can simply be installed in any corner that is reasonably square. A rectangular or square unit requires an opening of the correct width and height.