❄️ Are You Ready For Winter? CLICK HERE for our guide to winterizing your sprinkler system »
How To Install A Sink Drain Properly - Plumb University

How To Install A Sink Drain Properly

by Trevor Woods | Last Updated: April 22, 2020

When it comes time to replace a leaking sink drain or upgrade to one that matches your bathroom faucet you don’t need to call a professional for help. Installing a new sink drain assembly can be easily done in a few minutes with some basic hand tools.

We will walk you through this do-it-yourself project and show you how to hook up a leak-free sink drain. With our instructions, you can save time and money! But first, let’s cover some of the basics about sink drains and which style is best for you.

Buying A New Sink Drain 

When you go to purchase a new bathroom sink drain, you will come across a variety of styles and options which can be quite overwhelming. Fear not, drain assemblies are easy to figure out and pick the perfect one for your plumbing needs.

The first consideration you have to keep in mind is the size of the drain. Drain assemblies are measured via the threaded portion, as this is the part that goes through the sink. The diameter of a standard sink drain hole is around one and a half inches, and this diameter works well with most bathroom vanity sinks. You can find this sizing information on the drain packaging if you are unsure of the size you are buying.

Another factor in choosing the right vanity drain is whether or not your sink has an overflow. An overflow is a hole in the side of the sink itself that allows the bowl to drain and prevent the sink from overflowing in the case that the drain is shut. If you have a bathroom sink with an overflow outlet you need to opt for a drain assembly with an overflow opening to make sure the sink functions properly.

How To Tell If Your Drain Has An Overflow

Once you have determined whether you need a drain assembly with an overflow or not, now you can pick the material of the sink drain. Plastic drains are typically cheaper and easy to install while metal drains have tendency to last longer and retain leak free seals. Our preference is to choose higher quality metal drain assemblies due to their longevity and serviceability.

Comparing Plastic And Metal Drain Assemblies

Lastly it’s time to choose your finish. Chrome, brushed nickle, stainless steel, brass, bronze, the choices are seemingly endless! But we recommend that you select a finish that closely matches the appearance of your faucet.

There Is A Vast Variety Of Faucet Finishes

Type Of Sink Drain

There are various types of bathroom sink drains available, and it is up to you to decide what kind works best for you and your sink.

Press And Seal Or Clicker Drain

These are also called pop-up drains. Installation of these drains are a breeze and they are very easy to use. This drain style is an excellent choice for those who want a simple drain stopper or have limited strength or dexterity in their hands. All that you need to do is press down on the drain cover to activate the pop-up mechanism. 

Flip Or Pivot Drain

This sink drain is designed with a drain plug that can be flipped and rotated in place. This allows for fast draining speeds and easy access to clean the drain from any crud or hair build-up.

Twist And Turn Drain – Lift And Turn

Also called lift and turn drains, these are provided with a small knob on top which the drain cover can be lifted manually. There is no beneath-the-counter mechanism involved with these drains, and thus installation is quite easy. You can press the drain cover down and turn it to close the drain.

Strainer Drain – Grid Drain

These drains are without any closing function. The drain cover features a grid that makes sure that the water is able to flow through the drain easily while the larger items are blocked. You may find this style of a drain in commercial bathrooms or decorative vessel sinks.

Chain And Plug Drain

The “old school” style of sink drain assemblies. The rubber or plastic stopper has to be plugged and removed in these drains to stop the flow of water. They are operated manually and are mostly provided with a small basket so that the unwanted items do not accidentally fall down the drain when the stopper is removed. The chain and plug style drain is the perfect match for a vintage pedestal or cast iron sink.

Drain With A Pop-Up Rod

These drains are equipped with stoppers and lift rods. You need to pull up on the lift rod at the back of the faucet for their activation. This lift rod is attached to the drain linkage underneath the sink that lifts and closes the drain plunger. These sink drains require a little more work installing and fine-tuning the linkage but are worth the effort if it matches the lift rod that comes with your faucet.

Installing A Sink Drain

Once you have purchased the sink drain that works best for your sink, you can proceed with the installation. The sink pop-up stopper is quite straightforward and we will provide you with detailed instructions and tips to make installing a sink drain easy and leak-free!

Tools And Materials Needed

The first thing that you need to do is get the supplies ready. The tools and supplies that you will need for the process of installation include:

Got everything? Let’s get started!

How To

1. Disconnect The P-trap

We are assuming that you are replacing an existing sink drain so let’s get rid of the old drain assembly. This is perhaps the most challenging and messy part of the project.

The first step is to remove the P-trap from the drain (also known as the trap-arm) and the sink drain tailpiece. You can use channel-type pliers or an adjustable wrench to loosen the P-trap and remove it. Remember, lefty-loosey or turn the nuts counterclockwise to remove them.

Don’t Get Wet

The P-trap will have water inside it to prevent sewer gas from wafting up your sink so have a small bucket or container placed underneath the P-trap to catch the contents of the drain.

2. Remove The Old Drain Assembly

Once the P-trap is out of the way, you will have better access to remove the old drain assembly. The mounting nut can be removed from the tailpiece using channellock pliers or a wide mouth crescent wrench. Turn the nut counter-clockwise to unthread it and remove it from the old drain’s tail-piece.

You should be left with a washer and a rubber gasket stuck to the bottom of the sink itself. You can pry the old washer down by hand or with the help of a flat blade screwdriver. Just be cautious as any extra water that is trapped inside the sink is being held back by that rubber gasket. If the gasket is being stubborn you can either push the drain assembly up from the bottom and through the hole in the sink or carefully cut the rubber gasket with a utility knife.

After you have lifted the old drain out of the sink hole, clean the top and bottoms side of the sink. Remove any junk, silicone caulk, or old plumber’s putty with a paper towel and a scraper if necessary.

Tidy Up

Clean the drain’s mounting surfaces thoroughly. This makes for a flat surface for the new gaskets to seal against. Leftover debris can cause the new gaskets to deform and leak.

3. Prepare The New Drain Assembly

This is the first step when it comes to installing the shiny and new sink drain. Start by disassembling the drain and removing the mounting nut, washer and gasket from the drain stem.

If your new drain assembly comes with a gasket for the topside of the drain that seals it to the sink, slip it up against the drain cup. If you don’t have a gasket, apply a small bead of silicone caulk or plumbers putty to this flange instead.

4. Install The New Drain Assembly

Insert the drain assembly through the opening from the top side of the sink. If you have long enough arms, you can hold the drain in place while pushing the rubber gasket up the threaded section of the drain assembly from the bottom side.

If you can’t hold the drain in place, no worries! Simply lay a towel in the sink to protect the finish and place a heavy object like a book or bowl full of water over the drain.

Avoid Gasket Goof Up

Make sure you install the rubber gasket with the narrowest section against the bottom of the sink. These “stepped gaskets” are shaped like cones to help them seal properly to the underside of the sink.

After the rubber gasket has been slid up the drain stem, follow it up by the washer and then the nut. The washer acts as a friction disk that allows you to spin the nut without affecting the surface of the gasket. This makes for a gasket that seals flat and evenly.

5. Tighten The Drain Assembly

The rubber gasket on the bottom of your drain assembly is designed to be installed without the use of silicone caulk or sealant but if you want a little extra leak-free insurance, now is the time to add a thin layer to the rubber washer prior to tightening the drain assembly up.

Make sure the drain cup of the assembly is sitting flat and positioned evenly in the sink hole. If your drain model comes with a pop-up pivot lever, make sure the lift rod hole is pointing to the back of the sink towards the location of the pop-up rod. Spin on the nut with your hands at first to avoid cross-threading. Then tighten the nut on the drain stem slowly with your pliers or wrench, rechecking that the drain is still squarely positioned in the sink.

Not Too Tight

Avoid over-tightening the nut as this could deform the rubber gasket and cause leaks. However, at the same time, make sure that the nut is tightened enough so that it is secure and does not let the drain assembly spin in the drain opening.

6. Install The Drain Stopper

If you have clicker, flip, or plug style drain, you can easily install this from the topside of the sink.

However, if you are installing a drain with a pop-up lever you will need to install the stopper from the drain opening before crawling under the sink to finish connecting the linkage. The hole for the pop-up linkage should be facing toward the back of the sink as you push the stopper down into the drain.

After you have ensured that the stopper is in its position, the pivot rod has to be inserted into the opening on the side of the tailpiece from the underside of the sink. A plastic washer is usually present on each side of the plastic ball. The tip of the pivot rode has to slid through the opening in the stopper linkage inside the drain assembly.

Once you have skewered the pivot rod through the bottom loop of the drain plug the pivot rod nut has to be screwed on the threaded fitting present on the side of the tailpiece to make sure that the ball remains secured to the tailpiece.

Don’t tighten the pivot rod nut too tight. If you overtighten this nut the stopper will be too stiff to move up and down. Hand-tight is typically good enough. You can check for restrictions by gently pushing the pivot rod up and down. It should slide freely but also hold it’s position if you aren’t moving it.

7. Connect The Pop Up Lever

You’re almost complete! Turn the stopper in an open position so that you can connect the horizontal pivot rod to the vertical lever. Slide the faucet’s pop-up lever down via the hole you see behind the spout of the faucet.

The connecting strap has to be attached to the end of the vertical pop-up lever from below the sink. Make sure that the set-screw on the connecting strap is tight before you connect the strap to the horizontal pivot rod.

Now attach the vertical strap and horizontal pivot rod together with the spring clip onto the rod, ensuring that one end of the clip is present on either side of the strap. 

Now you can test out the drain stopper and make sure you can open and close the drain with the faucet’s lift rod. If you experience any binding or the pop-up plug doesn’t open and close completely you will have to adjust the connecting strap and spring clip. Be patient if it takes a few attempts to get the linkage perfect. A little fine-tuning will make for a flawlessly functioning drain!

8. Reconnect The Plumbing

Now reconnect the P-trap to the drain pipe and the drain tailpiece. This should go back together in the reverse order that you removed them. Apply any thread sealant if necessary and tighten everything up for the last time.

Lastly, fill the sink with water and test out the drain stopper. If set up correctly, the stopper should plug the sink and not let any water seep by. If it does, adjust the linkage for a firmer drain seal. Now you can drain the sink to make sure that there are no dribbles or drips coming from the plumbing underneath. Tighten as necessary. Done!

Conclusion

Great work! You’ve successfully replaced a sink drain assembly in your bathroom. We told you it wasn’t that complicated. Now you might be motivated to continue with some more “drain surgery”!

Happy Plumbing!

Trevor Woods is the founder of Plumb University® and he started in the plumbing and construction industry in 1997. Since then, his mission is to make plumbing repair and maintenance easy for everyone. And each year, he continues to help more people with their plumbing installation, care, and troubleshooting.