How to Locate a Shower Trap

Identify the location of the shower and access the area directly underneath it. If the shower is on a first floor, go to the basement or a crawl space. If the shower is on a second floor or the home has a slab foundation, go to the room directly opposite the shower so you can cut through the wall.

Draw a 12-inch by 12-inch square that is as close to the wall as possible; this is where the plumbing pipes always run. If you are working on a ceiling, draw the square on the ceiling at the top edge of the wall. If you are cutting through a wall, draw the square at the base of the wall near the floor.

Wear a dust mask and safety glasses. Cut through the wall or ceiling using a drywall saw or a reciprocating saw if it is plaster and lathe. Do not penetrate the wall more than approximately 1/2 inch to prevent damage to the pipes. Pull out the detached wall material until you can see the plumbing pipes.

Look at the pipes to identify a P-shaped pipe area that is approximately 6 to 8 inches long. This is the shower P-trap. If you don’t see an P-trap look for a 6- to 8-inch-tall vertical canister, which is an older type of shower trap.