fbpx Skip to Content

Replacing a Bathroom Vanity: Step By Step Instructions

As far as DIY projects are concerned, replacing a bathroom vanity is guaranteed to pay major dividends in updating the appearance of that space. And while it may seem daunting, replacing a bathroom vanity is a project well within the capabilities of most DIYers.

Read on for a step-by-step look at how to tackle and succeed with this transformative DIY project. You’ll also get answers to some of the most frequently asked questions about replacing a bathroom vanity.

Best of luck with your vanity replacement project. Remember to have some fun with it, and to take the lessons you learn to apply them to other DIY adventures.

White bathroom cabinet with black fixtures and a tan top.  Replacing a bathroom vanity

Removing the Existing Vanity

The first step in replacing a bathroom vanity is, of course, removing the old bathroom vanity. Taking care when getting the old vanity out of the bathroom can make the installation of your new vanity smoother and easier.

Read on for step-by-step instructions for removing your old bathroom vanity.

Disconnect the Sink and Water Lines

Before you do anything to remove your old vanity, locate the water valves at the back of the vanity and turn them off. Open the faucet or faucets to let any remaining water drain out. Then, place a bucket under the curved piece of pipe below the sink drain.

Remove the curved pipe, called a P-trap, by unscrewing the nuts on either end. If the pipe is plastic, you should be able to unscrew the nuts by hand. For metal pipe, you’ll need an adjustable wrench to remove the P-trap.

Person removing the P-trap on a metal pipe

Hold onto the P-trap while you’re unscrewing it. When it’s loose, turn it over so it drains into the bucket.

Next, grab a wrench and separate the water lines from the sink. Place your bucket under the sink connection and turn the water lines into it to catch any draining water.

If your water lines are not clearly marked as to which one carries hot water and which carries cold water, mark them now to avoid confusion later.

Separate the Old Vanity from the Bathroom Wall

When the drain and water lines are disconnected, you’re ready to get the vanity away from the bathroom wall. It should be screwed into the wall at various points along its back side, so you’ll need to locate and remove all of those screws.

Then, simply pull the vanity away from the wall. Be careful not to damage any drain or water lines as you remove the old vanity.

Once the old vanity is away from the wall and maneuvered out of the bathroom, you may notice some damage to the drywall behind it. Routinely, that damage can be addressed with the application of a bit of drywall putty and a few swipes with a paintbrush.

Mark the Space for the New Vanity

As you’re waiting for any drywall repairs or paint strokes to dry, grab a tape measure and a pencil. Mark the new vanity’s length, width, and height dimensions on the wall to help guide it into place.

Also, use a stud finder to locate and mark the location of wall studs within your new vanity’s dimensions.

If your vanity has a solid back, measure within the lines, marking the new vanity for the locations where water lines and drain lines emerge from the wall. Transfer those measurements to the inside back of the new vanity, and drill holes to accommodate getting the drain lines and water lines into it.

As you’re drilling holes for the drain lines and water lines, also mark the location of the studs you found. As with the water and drain lines, mark the stud locations on the inside back of the vanity cabinet. You’ll definitely need those marks as a guide for attaching the vanity to the wall as securely as possible.

If there are no studs along the wall where you’re installing your new vanity, you’ll need to install wall anchors. Mark their locations on the back of the vanity so you can find them and install the screws needed to secure the vanity to the wall.

Installing the New Vanity Cabinet

After you’ve marked the new vanity’s dimensions on the bathroom walls and cut holes for water and drain lines, slide the new vanity cabinet into place. You can make this part of the job easier by removing any doors or drawers from the vanity cabinet before sliding it against the wall.

Once the vanity is against the wall, further check its positioning with a level. If it’s not level, install wood shims along the cabinet’s bottom front edge until it is level.

Attach the Cabinet to the Wall

You’re now ready for the next step in replacing your bathroom vanity. To attach the vanity cabinet to the wall, first locate the marks you made to identify the locations of wall studs or wall anchors. Next, use wood screws to secure the vanity cabinet to the wall.

Be sure that your screws are long enough to fit through the vanity cabinet, the wall behind it, and well into the studs to which it will be anchored.

A person attaching a new bathroom sink to the wall

Installing the New Vanity Top

If your vanity didn’t come with a pre-installed top, apply a thin bead of caulk around the top edges of the vanity cabinet. Once that’s done, you can set the new top in place. If you’ve been careful to install the vanity cabinet so that it sits square and level, setting the top in place should be simple.

Once the top is in place, run a bead of caulk around its top edge to seal the backside of the vanity from moisture infiltration. Use a caulk finishing tool to push the caulk firmly and neatly into the edge of the vanity top.

Installing the Faucet and Connecting the Plumbing

At this point, all that’s left to do in replacing your bathroom vanity is connecting its faucet and sink to the water and drain lines. If you’re installing a new faucet, the manufacturer likely will have included installation instructions. If that’s not the case, or if you’re reinstalling your existing faucet, read on for guidance.

If you have a double vanity, follow the same instructions for both faucets. Your first step will be to insert the faucet’s water line connections through the holes pre-drilled in the vanity top. Once the faucet is in, you’ll move on to dealing with the water lines and drain pipes.

Place the Drain Body

Turning your attention to the sink drain, drop the first section of the drain line, which will connect to the P-trap, through the drain hole. Secure this section of drain line to the bottom of the sink with the lock nut that is part of the sink drain assembly.

Insert the Ball Rod and Lift Rod

Next, you’ll be installing the assembly that opens and closes the drain when you pull or push the lift rod located between the faucet handles. Working under the sink, install the ball rod through the hole in the side of the drain pipe. Tighten the sleeve connected with the ball rod to prevent leaks.

Next, attach the ball rod to the lift rod strap. Make sure the ball rod is fully down before attaching it to the lift rod strap. When properly installed, operating the lift rod moves the ball road into or out of the drain pipe.

When the lift rod is in the down position, water flows freely. When the lift rod is in the up position, water is held in the sink.

Person holding new bathroom water lines

Connect the Water Lines

The final step in replacing your bathroom vanity is reconnecting the water lines to the faucet. Simply use the locknut on each water line to attach it to the faucet shanks now protruding underneath the vanity top.

Be sure to reconnect the hot water line to the hot water faucet. Typically, the hot water faucet is on the left side of the sink as you’re looking toward it from the front.

Replacing a Bathroom Vanity Frequently Asked Questions

You’re now equipped with the basic information you’ll need for replacing a bathroom vanity. But if you’re like most DIYers, you’ll almost certainly want to know more about tackling this project. Read on for answers to some frequently asked questions about replacing a bathroom vanity.

Are there standard sizes for bathroom vanities?

Standard vanity widths are 24, 30, 36, 48, 60, or 72 inches, with standard depths of 21, 22, or 23 inches. Your replacement vanity top will need to be 1 inch wider and deeper than your vanity cabinet.

Standard vanity heights range from 30 to 36 inches. As you’re choosing a replacement vanity, consider who will be using it most often. If you’re replacing a bathroom vanity in a space frequented by youngsters, choose a lower standard height.

When installing a new bathroom vanity, make sure that there are at least 18 inches of space between the vanity and the base of the toilet. Also, there should be at least 30 inches between the vanity and the bathtub or shower.

How can water damage issues be addressed while replacing a bathroom vanity?

An ongoing concern for home maintenance is moisture damage. To help minimize moisture issues in connection with replacing a bathroom vanity, a good first step is to avoid vanities constructed of particleboard or MDF (medium-density fiberboard).

Instead, choose a vanity made either of plywood or solid wood. Those two options for replacing a bathroom vanity will be far less susceptible to moisture infiltration and damage than particleboard or MDF.

In addition, applying waterproof paint or polyurethane varnish to your wood vanity cabinet can help prevent moisture damage as part of replacing a bathroom vanity.

Once your new vanity is installed, check under the cabinet regularly for signs of leakage from drains or pipes.

Is just replacing a bathroom vanity top a possibility for a DIY project?

If you don’t have the time, desire or need to replace an entire bathroom vanity, it’s more than OK simply to replace the vanity countertop. To do so, first measure the dimensions of your vanity cabinet.

As a reminder, standard vanity widths are 24, 30, 36, 48, 60 or 72 inches, and standard depths are 21, 22 or 23 inches.

Your replacement vanity top will need to be 1 inch wider and deeper than your vanity cabinet. If you have a standard-size vanity, you can find correctly sized replacement vanity tops at home improvement warehouses. If you have a non-standard vanity, you’ll need to visit a custom counter fabricator.

Pre-made vanity tops will start in the $100 range. Prices for custom vanity tops will start at around $500. In terms of material, porcelain is your least expensive option, at about $7 to $19 per square foot. A granite slab vanity top will cost approximately $40 to $60 per square foot.

Two white bathroom vanities with black fixtures in a grey and white bathroom

Wrapping up Replacing a Bathroom Vanity

Now that you’ve learned the tricks for replacing a bathroom vanity, it’s time to get out your tools and head to the home improvement store. Within just a short time of getting your new vanity to your home, you’ll have finished a DIY project of which you can be proud.

When you’re done with replacing your bathroom vanity, you can check other posts at DIY Painting Tips for help with more bathroom projects. You’ll find posts on everything from mildew and mold issues to the easiest way to paint behind a toilet.

Good luck with replacing your bathroom vanity, and with whatever other DIY bathroom improvement projects you may decide to pursue.