How to Make a Mud Tray for a Shower

Use a jigsaw to cut a 3/4-inch plywood board to fit the dimensions of the shower floor. Cut a hole in the plywood for the shower drain. One way to mark the location of the drain hole on the plywood is to measure the distance from the edges of the shower to the drain hole, and mark the distance on the plywood. Another way is to place the drain assembly into the drain hole, and brush paint around the edges. Lay the plywood on top of the drain assembly, and the paint will mark the correct location of the drain hole onto the plywood.

Lay the plywood into position on the floor, lining up the hole in the board with the drain hole in the floor.

Nail a 2-by-10 board to the base of the framing where each of the three shower walls will be installed. Stand the 2-by-10s on their narrow edge along the perimeter of the plywood when installing them. This locks the plywood in place while forming three of the walls for the mud tray.

Stack three 2-by-4 boards on the edge of the shower where the door or shower curtain will be, and nail them to the floor. Lay the boards on their broad edge when stacking them.

Lay roofing felt on top of the entire piece of plywood, and staple it to the board.

Cover the roofing felt with mesh, and staple it to the plywood.

Cut a hole through the roofing felt and mesh over the location of the drain hole with a utility knife.

Insert the bottom flange of the drain assembly into the drain hole. The drain assembly is the pipe that extends through the bottom of the shower and connects to the pipes that lead to your home's drainage system.

Prepare the mud, following the instructions on the packaging. Place duct tape over the drain assembly to prevent the mud from falling down the drain hole. Pour the mud onto the shower floor.

Drag a 2-by-4 board over the mud to smooth the surface. To improve drainage in the shower, create a slope which leaves the mud about 1 1/2 inches higher around the edges of the tray than around the drain hole.