How to Install Rough in Plumbing for a Bathroom

A bathroom.
  • 3-5 hours
  • Advanced
  • 100-200
What You'll Need
Copper supply pipe
1¼ inch PVC drain pipe
Propane torch
PVC glue
3/8 inch compression fittings
Pipe cutter

A bathroom rough plumbing is not complete if you are going to be having a laundry area built in along with the rest of the fixtures. Many people opt to have the laundry area in a separate room or in the basement. However, there are times when the laundry area is placed in the bathroom in a closet or nook area. Rough plumbing a washer is much the same as with any other type of fixture that you are installing. Once the rough plumbing is ready for the washer, you can then go into setting the fixtures into place as well as finishing off the project.

Step 1 - Tie Drain into Waste Line and Vent

Depending on where the washer is going to be located you should already have the main waste water pipe that the rest of the fixtures are running into. Use another coupling and run the drain pipe under the floor to the wall where the washer will be located. It should bend with a 90-degree angle up the wall and in between two studs. The final height of the drain pipe should be approximately 32 inches. You should also place the drain coupling near the vent pipe so that the water runs more efficiently.

Step 2 - Install Water Supply Pipes

Run the water supply lines under the floor to the area where the washer is going to be located. You will need to have both a hot and cold water supply line. Once you reach the wall, use a 90-degree elbow and run the piping up the side of the wall. The hot water line is on the left with the cold water line on the right of the drain pipe. They should be 3 to 4 inches away from the drain pipe, but on either side. The final height of the supply lines should be the same as the drain pipe with a shut off valve on the top.

Step 3 - Check All Connections

Once the rough plumbing for the washer has been completed you will need to go back and recheck all of the connections to make sure they are good for soldering and gluing. Check every joint, connection, elbow, and fitting to ensure that the fixtures will be able to be installed easily and correctly.

Step 4 - Solder and Glue

Fire up the propane tank and solder all of the copper pipe connections. Once all of the copper pipe is secure with the solder, you will also need to secure it to joists and studs with metal pipe holders. They slip over the pipe and are then screwed on either side. This is to keep the pipes from rattling and banging into the wood in the event air gets into the pipes. Once the copper pipes are taken care of, go over all of the PVC pipes and glue them together.

Step 5 - Finish Off With Coverings

Once the rough plumbing is completed you can then finish off with wall coverings, flooring, and small touches like a cover for the washer drain and supply lines.