how to install bathroom sink drain

Although plumbing projects are far from being the most glamorous part of a renovation or repair job, they are necessary. Many jobs you will probably want to leave to the professionals. However, being able to repair or install a bathroom sink drain is a skill that any DIYer can handle.

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Bathrooms are notorious for developing tiny issues that can drive one crazy. The need to know how to fix running toilets, leaky drain pipes, dripping faucets just goes with the territory.

Luckily, these are very basic plumbing skills that anyone can learn. Knowing how to perform these common repairs will go a long way in making your life easier.

How To Install Bathroom Sink Drain - pin

Parts of a Sink Drain

pop-up stopper
lift rod
pivot rod
Extention strap
pop-up (from top to bottom – flange, rubber washer, pop-up body, rubber gasket, flat washer, locking nut)
tailpiece
waste arm
waste line connector (solvent welded to waste line. May be screwed or glued to waste arm – depending on the type)
slip washer
reducing washer
slip nut
j-bend
extension pipe (purchased separately)

Things to Know Before Attempting To Install a Bathroom Sink Drain

Always do a preliminary test fit, measure, and make cuts before finalizing the installation.

Slip washers and gaskets are always placed with the bevel facing the connection joint (or where the two ends will meet).

Materials You Will Need:

Sink Drain Kit*
P-Trap Kit*
Extension tube* – needed when the tail pipe isn't long enough to reach the p-trap
Plumber's putty* – some drain kits come with a washer that eliminates the need for plumber's putty.

Tools You Will Need:

Channel lock Pliers*
Hacksaw* or pipe cutter

How to Install a Bathroom Pop-Up Sink Drain

Step 1 – Roll plumber's putty between your hands to form a piece about the size of a gummy worm. Place the rolled putty around the underside of the sink flange.

NOTE – Some drain kits come with a flange washer – as this one did. In this case, you would not use plumbers putty.

Place the flange in the sink hole. Press firmly into place.

Step 2 – If not already done for you, assemble the pop-up body by placing the locking nut and flat washer over the threads of the pop-up. Slide the rubber gasket on last. The gasket's tapered end should face up.

Step 3 – Screw the pop-up body to the flange through the hole from the underside of the sink. Make sure the pivot rod opening faces the back of the sink.

Step 4 – Hand tighten the locking nut on the pop-up body until the gasket fits snug against the underside of the sink.

Using the channel lock pliers, tighten two to three additional rotations. Do not overtighten. Wipe away the excess putty around the flange as needed.

Step 5 – Drop the pop-up stopper down into the drain opening. Make sure the hole for the pivot rod is facing the rear of the sink.

Step 6 – Insert the lift rod through the top of the sink faucet.

How To Install Bathroom pop-up Sink Drain

Step 7 – Attach the extension strap to the lift rod from underneath the sink.

Step 6 – Slide one end of the pivot rod into both the pop-up body and through the hole in the stopper. Tighten the nut over the pivot rod opening.

Step 7 – Slide the other end of the pivot rod through the extension strap and the attachment clip as shown above. Test the pop-up and make adjustments as needed with the pivot rod and the extension strap connections.

Step 8 – Wrap thread tape around the threads of the tailpiece and screw the tailpiece to the pop-up body. (Thread tape should be included with your drain kit).

Step 9 – If a tailpiece extension is needed, slide a slip nut followed by a reducing washer over the end of the tailpiece. Make sure that the beveled edge of the washer is pointing down.

Then, slide the extension over the tailpiece and tighten the nut.

How To Install P-Trap to Bathroom Sink Drain

Step 1 – Slide two slip nuts over the waste line arm. One should face the waste out and one should face the p-trap. Add a slip washer with the bevel facing the waste-out connection.

Step 2 – Attach the waste line arm to the wall. Loosely tighten the slip nut.

Step 3 – Slide a slip nut followed by a slip washer over the bottom of the extension pipe (over tailpiece if not using an extension). Attach the j-bend and tighten the nut.

Step 4 – Turn the j-bend pipe until it meets up with the waste line arm. Make adjustments as needed in the waste arm-to-wall connections in order to get the proper alignment. Attach the j-bend pipe to the waste line arm.

Step 5 – Tighten down all the nuts and connections.

Step 6 – Test for leaks and make adjustments as needed.

Final Comments

Most sinks, whether the kitchen or bath, will follow this basic process. There may be some slight deviations for special situations or designs, but once you understand the process, it should be easy to figure out any change-ups that are needed.

Double sinks can connect to the same waste line with the addition of a few extra connectors. Flexible pipe can be used when the wall connections are off-center.

Rachel is a home improvement expert with more than 20 years of experience in renovations, carpentry, and interior design and has more than 10 years experience in graphic and web design. She used the combination of her experience and knowledge to start her own digital media publishing company where she shares her knowledge across three different websites.

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