Extend Bathroom Sink Drain Pipe

Extending the drain pipe under a bathroom sink is a relatively simple plumbing task that can be completed in a few hours with the right tools and materials. This is a common project when replacing a sink or vanity, or when adding a new fixture, such as a garbage disposal. By following these steps, you can easily extend the drain pipe under your bathroom sink.

Tools and Materials You'll Need:

Adjustable wrench
Slip joint pliers
PVC pipe cutter
PVC cement
PVC pipe (same diameter as drain pipe)
PVC elbow (same diameter as drain pipe)
PVC cleanout plug (optional)
Teflon tape

Step-by-Step Instructions:

Turn off the water supply to the sink.

Locate the shut-off valves under the sink and turn them clockwise to close them. 2.

Disconnect the old drain pipe.

Use an adjustable wrench to loosen the nuts that connect the drain pipe to the sink and P-trap. Carefully remove the old drain pipe. 3.

Measure and cut the new drain pipe.

Measure the distance between the sink drain and the desired location of the new drain pipe. Cut the new PVC pipe to this length using a PVC pipe cutter. 4.

Assemble the new drain pipe.

Apply a thin layer of PVC cement to the inside of the PVC elbow and the end of the new drain pipe. Insert the drain pipe into the elbow and twist it to connect them. Allow the cement to dry for a few minutes. 5.

Attach the new drain pipe to the sink.

Apply a thin layer of Teflon tape to the threads of the sink drain. Screw the new drain pipe onto the sink drain and tighten it with an adjustable wrench. 6.

Connect the new drain pipe to the P-trap.

Apply a thin layer of Teflon tape to the threads of the P-trap inlet. Screw the new drain pipe into the P-trap inlet and tighten it with an adjustable wrench. 7.

Install a cleanout plug (optional).

If desired, install a PVC cleanout plug at the end of the new drain pipe. This will allow you to access the drain pipe for cleaning or maintenance in the future. 8.

Turn on the water supply and check for leaks.

Open the shut-off valves under the sink and turn on the water. Check all of the connections for leaks. If you find any leaks, tighten the connections until they stop.

Tips:

Use a level to make sure that the new drain pipe is installed at a slight downward angle towards the drain.
Do not overtighten the connections, as this can damage the pipes or fittings.
If you are not comfortable working with plumbing, it is best to hire a licensed plumber to perform this task.