How to Install Concrete Walling in a Shower

Measure the width of your shower walls and transfer those measurements to your sheets of concrete board. Sheets normally come in either 3-by-5-foot boards or 4-by-8-foot boards. Order sheets according to the size of your shower. If possible, install full sheets, but almost all showers require that you cut the sheets down to size.

Cut the pieces of concrete board as required with a utility knife. Mark the top and bottom edge of a piece with the tape measure and pencil, then snap a chalk line between the two marks to give you a line to cut. Slice the piece of board along this chalk line with the utility knife, then snap the piece with both hands against the line, folding it against the scored mark. Use the utility knife to cut the back side free after you snap the pieces.

Place the pieces of concrete board on the wall. Mount the pieces on the wall by setting the drywall screws through the boards into the wall studs. Keep at least an eighth-inch gap between all pieces. Place the screws every 3 to 4 inches, or according to the marks that are already on the face of the concrete board as a reference line. (Not all boards come with reference marks.)

Fill the gaps between all pieces with silicone caulk, as this will allow for seasonal movement when the house expands and shrinks during the warmer and cooler weather of the year. Leave the silicone caulk to dry for at least 24 hours before installing your preferred method of waterproofing on top of the concrete board.