How to Mud a Shower Pan

Shower pans are installed over a mud, or mortar, base.

Remodeling a bathroom can be a very extensive project that can involve installing a new shower. When you're building a new shower, one step is building the base for the shower pan. This process is sometimes called mudding, although you build the base out of mortar. The base is sloped to fit the shape of the shower pan and supports the pan and you when you're in the shower.

Things You'll Need

• 3/4-inch plywood
• Jigsaw
• 2-by-4-inch boards
• 2-by-10-inch boards
• Hammer
• Nails
• Roofing felt
• Mesh
• Staple gun
• Staples
• Utility knife
• Shower drain assembly
• Mortar
• Trowel

Instructions

1. Lay a 3/4-inch plywood board on the floor where you're building the shower. Cut a hole in the board for the drain hole with a jigsaw.

2. Build the frame for the drain pan by nailing three 2-by-4 boards to the floor where the shower door will be installed and one 2-by-10 board at the bottom of the studs where the walls will be.

3. Lay roofing felt on top of the plywood. Staple it to the plywood and cut a hole in it for the drain.

4. Cover the roofing felt with mesh and staple it to the plywood. Cut a hole in the mesh for the drain hole.

5. Slide the bottom flange of the drainpipe assembly into the drain hole.

6. Mix a batch of mortar (the "mud"), following the manufacturer's instructions.

7. Add the mortar to the shower base with a trowel. Use more mortar around the edges of the shower pan than around the drain hole because it will be easier to slope.

8. Slope the mud in the base of the shower by dragging a 2-by-4 board across the surface. The mud should be about 1 1/2 inches higher around the edge of the base than around the drain hole. Allow the mud to set for at least four to five days.

References

• Mr. Tile: Installing a Leak-Proof Shower Pan
• This Old House; How to Replace a Shower Pan; Richard Trethewey
• Hoagy.org: How to Build a Shower Pan