How to Rough In Shower Systems

Waste-Vent System

• 1

  Mark, according to the plumbing plan, the locations of the shower, water supply pipes and the drains on the sub floor with masking tape. Cut out a 12-inch square opening from the subfloor for the shower drain. Drill 1- inch diameter holes in the subfloor for each water supply riser on the plan.

• 2

  Establish a route for a 2-inch vertical waste vent pipe running from the basement. This pipe should be no more than 5 feet from the shower. Mark a route for the horizontal drain pipe running from the shower drain to the waste vent pipe. Cut 3-inch diameter holes through the center of the floor joists along this route for the shower drain pipe.

• 3

  Cut a 4.5-by-12-inch notch in the bottom plate of the wall where you planned to install the vertical waste vent pipe. Make a similar cut at the bottom of the joist cavity. Locate the area directly under this notch on the basement ceiling and drill a test hole. Shine a very bright light through the hole. Then, go back to the bathroom and look into the notch. If you see the light , go back to the basement and cut 4.5-inch diameter hole centered over the test hole.

• 4

  Measure and cut a length of 2-inch diameter PVC pipe to reach from the bathroom floor to the bottom of the ceiling joists in the basement. Solvent-glue the 90-degree, 2-inch elbow to the top of the vertical waste vent using the PVC primer and PVC cement according to the manufacturer's instructions. Ensure the elbow faces towards the drain location.

• 5

  Cut into the main waste vent stack in the basement. Solvent glue a waste vent T-connector into the space cut out of the stack. Solvent glue a Y-connector with 45-degree elbows to the basement end of the shower drain. Solvent glue horizontal drain pipes from the waste T- connector to the Y-connector. Support the horizontal pipes every 4 feet with vinyl pipe straps. Solvent glue cleanout plugs to the open inlets of the Y-connector.

• 6

  Install an S-trap at the drain location. Dry fit a 2-inch drain pipe from the shower drain S-trap to the elbow at the waste-vent pipe. Use whatever fittings are necessary to route the pipe from the drain hole to the waste vent pipe. Cut a hole in the wall plate where the vent to the attic will be located. This must be within 5 feet of the trap. Add the vent T-connector to the drain pipe layout at the hole. Ensure the overall drain layout slopes downward, away from the shower drain, at 1/4 inch per foot of pipe. When satisfied with the layout, solvent glue all the pieces together.

• 7

  Cut a length of 1.5-inch diameter PVC pipe that reaches from the vent T-connector to at least 1 foot into the attic. Solvent glue an elbow fitting facing towards the main waste-vent stack. Cut into the main vent stack and add the second waste vent T-connector. Solvent glue horizontal pipe from the shower vent pipe to the vent stack T-connector.

Water Supply

• 8

  Shut off the main water supply. Cut into the existing supply pipes and install T-fittings for new branch lines using the method appropriate to the material of the supply line.

• 9

  Remove the subfloor and notch the joists to fit 3/4-inch water supply pipes. Extend the supply lines through the notched joists to the location of the wet wall of the shower. This is the wall that will contain all the water lines for the shower. Use elbows and water supply pipes to create vertical risers where the wet wall will be created.

• 10

  Support the risers from below with a 3/4-inch board nailed between the joists. The risers should extend at least 6 inches above floor level.

• 11

  Attach caps to the risers. These will be removed and replaced with shut off valves after the shower is constructed. Turn on the main water supply and inspect the lines for leaks.