How to Replace a Plastic Fitter Shower With Tile

Remove any accessories and disconnect the shower head, faucet handles, spout, drain and anything else that can be unscrewed or otherwise removed from the shower.

Slice the caulking around each wall panel and the shower base using a utility knife.

Remove the wall panels and shower base. Unscrew any fasteners that may be holding the panels together or to the wall studs. Pry the panels and base away from the underlying materials using a pry bar or wrecking bar.

Remove any remaining materials so that the subfloor and wall studs are exposed. If parts of the drain remain, remove these so that only the drain opening remains.

Build the shower curb. Measure the opening at the shower threshold, cut three lengths of 2x4 board to this size, stack them at the opening and secure them to the floor joists and wall studs using 16d galvanized nails.

Build the frame for the shower pan. Measure the openings between the wall studs and cut sections of 2x10 to this size. Install a section of 2x10 in each stud bay to form a low wall around the shower perimeter.

Cut a section of building paper to fit the shower floor and staple it to the subfloor. Cut a hole for the drain opening.

Glue the bottom piece of a three-piece shower drain into the drain opening. Stuff a rag into the opening to keep loose globs of mortar out.

Calculate and plan for the establishment of the slope in the pre-pan mortar layer. The shower floor should slope toward the drain at a rate of at least 1/4 inch per foot of floor. Determine the total required rise by measuring the distance between the center of the drain and the farthest wall and multiplying this distance, in feet, by 1/4 to determine, in inches, the necessary change in elevation. Use a level to mark the height of the top of the drain flange on the wall, then measure up the distance of the total required rise and use the level to draw a line around the shower perimeter at this height.

Cut and staple a section of metal lath to fit the shower floor. Leave a small gap around the drain piece.

Mix the mortar according to the manufacturer's instructions, or so that it has a fairly dry consistency, and pack it into the metal lath, building up the mortar between the drain and the line drawn on the wall to reflect the desired slope. Once the shape of the mortar pre-pan has been roughly established, run a straightedge or level over the mortar with one end on the drain and the other at the line. Identify and correct any low or high spots in the mortar. Let the mortar cure before continuing.

Attach waterproof membrane to the shower pan. Cut a section of membrane so that it extends 8 inches up each wall and up and over the curb. Cut slits for the drain bolts and a hole for the drain opening. Glue the membrane to the underlying material using an adhesive suitable for use with the specific membrane material. For additional security, staple the material to the wood. Only place staples above the level of the curb and on the top and outside of the curb.

Glue dam corners into each interior corner of the curb to provide additional reinforcement.

Waterproof the walls. Staple waterproofing membrane, plastic sheeting or waterproof building paper to the wall studs. If possible, use one solid piece. If multiple pieces must be used, be sure to overlap the end by several inches. Make the wall membrane overlap the membrane for the pan, using adhesive to create a watertight seal.

Install cement backerboard on the shower walls. To cut pieces of board to fit or accommodate fixtures, score the board with a utility knife before snapping it or pounding the unwanted area out. Use galvanized nails to secure the backerboard to the wall studs. Only place nails above the level of the curb and cover each nail with silicone caulk.

Attach the middle and top drain pieces. Remove the rag from the drain opening. Use drain bolts to secure the middle drain piece, tightening them to create a watertight seal. Screw the top drain piece in, adjusting its height to reflect the height of the planned mortar bed plus the thickness of the tiles. The mortar bed should be about 1 1/2 inches thick.

Draw a line around the shower perimeter that reflects the height of the planned mortar bed.

Place mortar in the shower pan, building the bed up to about half of its planned thickness.

Cut a section of metal lath to fit the shower floor, leaving an opening for the drain, and press it into the mortar.

Build up the remainder of the mortar bed. Once the rough shape of the bed is established, run a straightedge or level between the drain and the line drawn around the wall to identify and correct any low or high spots. Smooth the surface by running a float over the mortar. Let the mortar cure before continuing.

Tile the floor and walls. Work in a small area at a time. Spread a thin layer of thinset mortar over the area and press one tile at a time into the mortar. Use tile spacers between tiles to maintain uniform spacing. Cut tiles to accommodate the desired design using a tile cutters or other tool. Check the tiles regularly to make sure that they are level and even, making adjustments as needed before the mortar begins to set.

Complete the curb. Cut and bend a section of metal lath to fit over the curb, stapling it on the top and outer side of the curb. Pack mortar into the metal lath on the sides, running a trowel or float over the mortar while using a thin board set on the top of the curb as a guide. Let this mortar cure before spreading thinset mortar over it with a notched trowel. Cut tiles for the curb so that the tiles on the outside extend slightly above the tiles for the inside. Press the tiles into the mortar. Once these tiles are secured, pack mortar into the top of the curb and press bullnose cap tiles into the mortar.

Grout all of the tiled surfaces to fill in the spaces between tiles.

Reinstall any fixtures that were previously removed.

Run a bead of silicone caulk over all joints and around fixtures.