Bathoom vanity and plumbing installation

A lot of people ask us how difficult it is to remove their old vanity, and install their new one.  Most are able to do a little demo, as well as get the new vanity in place, but have questions when it comes to plumbing.  If you have no experience with plumbing, don’t worry.  With a little bit of training, it is a project you can easily do yourself.  My husband and I recently changed out ours, and wanted to share how we did it. He did most of the heavy work, but I helped where I could- I disconnected the existing faucet and drain, he did the demo to get the old vanity out. He moved the new vanity into place and I attached the new faucet and drain.  And I am 8 months pregnant- if I can do it, anyone can!!


At the bottom of the page, you will find links to my 2 favorite you tube videos covering these topics, if you need a visual to accompany these directions.



Here’s a step by step what you need to know to take out the old drain and faucet


-start by turning off the supply valves that are connected to the faucet- to do this, find where the piping comes out from the wall.  There will be one for hot and one for cold.  Turn each of these clockwise to shut off the water supply

-Turn on the faucet to eliminate any existing water

– Put a towel on the floor below the supply valves, and slowly unscrew the faucet supply lines from the supply valves.  Some water will leak out of the lines- hence the towel.

-once disconnected, you are ready to take apart the drain.


– The portion of your drain that comes from the sink to connect to your plumbing is called the tailpiece.  This connects to your j trap, which connects to your wall tube( referred to here as the drain elbow), which connects to the stub out  in the wall.  Each one of these connections is held together with a nut and washer

FYI- you will commonly hear the bathroom drain referred to as the p trap- the p trap is made from the combination of the j trap and the wall tube put together, giving it the shape of the letter “p”

-Start by placing a bucket under the drain. There will be some water in the j trap that you will want to catch

-unscrew the nut that connects the tailpiece and the trap, until loose.  If the fittings are plastic, you should be able to do this by hand.  If the drain is metal, you will want to use either a pipe wrench or adjustable pliers.

-unscrew the nut that attaches the j trap to the wall tube, until disconnected, and remove the j trap

-unscrew the nut that attaches the wall tube to the stub out, and remove the wall tube.

FYI- if the plumbing fixtures you are removing are metal, I highly recommend that you replace them with plastic.  They will last decades, and won’t corrode like the metal piping.

now you are disconnected, and can start removing the top and sink.  Start by using a box cutter and sever the caulk connection between the countertop and the vanity base itself, as well as where it is caulked to the wall behind.

-use a crowbar or chisel to pry the top away and off.

– now you can remove the vanity base itself.  Depending on how it is attached to the wall and floor, this will be done in a variety of ways. The base will most likely be screwed into the wall, so start by removing any screws or attachments.  If the cabinet is caulked to the wall, use a box cutter to sever the attachment, and either a crowbar or chisel and hammer to pry it loose. Remove everything from the workspace, and give the area a good cleaning

– bring your new cabinet into the space, and get it lined up before attaching it.  Once you have the position that you want, secure it to the wall in one of 2 ways- if there are studs for you to attach it to, drill through the cabinet, directly into the studs.  If there are no studs where you need to attach, you will want to use anchors to grip the screws. Once your base is secure, you are ready for the top.

-To make installation of your faucet easier, I recommend attaching the faucet to the countertop BEFORE attaching the top to the base.  This includes attaching the supply lines to the faucet- having to attach them from underneath can be very difficult, especially if you have an undermount sink. How to attach the faucet will depend on the maker- refer to the manufacturer’s instructions.

-On the top rim of the cabinet, run a bead of either silicone adhesive or caulk, and set your counter on top, with the supply lines hanging down into the cabinet. Then, caulk along the meeting of the countertop and the back wall.

– You are now ready to attach the plumbing!

-Depending on the drain that you have, there will be some variation in these instructions.  I will go over the instructions for the manual pop up umbrella drains that we sell in our shop.

-Start by unscrewing the tailpiece from the top of the drain.  Next, remove the metal nut, as well as all of the plastic washers.  This leaves you holding just the top portion of the drain.

– Apply a coil of plumbers putty to the underlip of this top portion, between where the drain and the sink will meet.  The coil should be about as thick as your pinky finger. Then insert the top portion of the drain through the top of the sink.

-From underneath, you want to re attach the curved washer first, with the curve facing up, like a bowl. Then the rigid plastic washer, followed by the metal nut. Tighten these very well, using adjustable pliers or a plumbing wrench.  The excess plumbers putty will squeeze out of the top, and is easily cleaned by hand

-Attach the tailpiece to the drain, and tighten well using adjustable pliers or a plumbing wrench

– loosely assemble the j trap and wall tube, and loosely  attach to the stubout.  Once the p trap is in place, finish tightening all of the nuts by hand.  If the trap is plastic, you do not need to use any tools to tighten these.  If the trap is metal, you will need to use tools to tighten the connections.

-Now it is time to turn the supply valves to the faucet on.  Do this slowly, and check for leaks from the wall source.  Then turn on your faucet.  There will be some air in the lines, so it may spit out at first.  Check both the hot and cold.  While the faucet is running, check under the sink for leaks coming from any of the connections.  If there are any leaks, tighten these connections until dry.

-The last test is to stop up the drain and fill the sink.  Once full, empty the sink, and check for leaks one more time.

-Congratulations, you are done!

below are my 2 favorite links for you tube how to- these guys are great! Enjoy!