Install a Vanity Sink Overview
This is what the bathroom looked like before trying to install a vanity sink.
Sinks and vanities get more use than any other fixture in your house. It’s no wonder they can look tired and run-down after five or 10 years. Fortunately, changing a vanity is relatively easy, and if you paint the walls at the same time, you can achieve a stunning transformation. In this article, we’ll show you how to remove your old vanity and install a new one. All you need are basic carpentry and plumbing skills and usually just one weekend.
We wanted an elegant, fine-furniture look for our bath, so we went with a special-order multiple-piece vanity and matching solid-surface top from a local home center. You may decide to purchase a one-piece cabinet with a matching top, which is a bit easier to install, but the basic how-to will be the same. Just follow our photos and read the text for buying information and additional tips. New vanities (4 ft. long) can cost anywhere from $150 for an off-the-shelf model at a home center up to $3,000 for a first-class piece of fine furniture. The top can be anything from cultured marble with a molded bowl starting at $140, a plastic laminate top for about the same price, or a solid marble or granite top costing as much as $2,000.While some of these prices might knock your socks off, keep in mind you’ll be able to find something in between to fit your budget and taste. Our setup was about $1,200 for the cabinets and about $950 for the solid-surface top with molded bowl.
Removing your old vanity may be the toughest part of the job
Photo 1: Shut off the water
Shut off the water to your sink before you disconnect your faucet supply tubes. Look for shutoff valves under the sink and turn them off. If you don’t have shutoff valves, shut off the water supply where it enters your house. Turn on the sink faucet to make sure the water is completely off.
Photo 2: Disconnect the pipes
Unscrew the supply tube nuts. Loosen both slip nuts and remove the P-trap. The curved pipe will be full of dirty water, so have a pan and a rag handy to wipe any spill. Stuff a moist rag into the waste pipe to block sewer odor until you’re ready to reconnect the trap.
Photo 3: Remove the backsplash
Chisel away the tile backsplash before removing the vanity top. If you have a plastic laminate backsplash, just cut the caulk seam with a utility knife where the backsplash meets the wall.
Photo 4: Remove the top
Look for screws that fasten the top to the cabinet and remove them. Your vanity top may be glued instead of screwed to the cabinet. Use your long-blade scraper to slice through any visible glue and then pry the top off the cabinet. You may need to wiggle it back and forth a bit to free it from the wall and the cabinet.
Pull the top free from the vanity and try to lift it straight out to minimize damage to the surrounding walls and fixtures. Get some help; it may be heavier than you think.
Photo 6: Remove the vanity
Unscrew the vanity from the wall. If you don’t see screws, look for large nails and use a pry bar to remove them. While you’re at it, mark the wall stud locations. They’ll come in handy later.
The first thing to do, of course, is to shut off the water supply (Photo 1).Next, disconnect the plumbing connections that supply water to the faucet and the waste trap below the sink. Both nuts on the trap unscrew counterclockwise. If you have shutoff valves under the vanity that supply the hot and cold water, be prepared for the possibility that they may leak even after you’ve turned them off (clockwise). If they’ve been there for 20 years, the valves may be corroded just enough to let a little water trickle out. If this is the case, shut off the main water supply and then replace the shutoff valves. You can get replacements at any hardware store or home center.
Instead of coming out through the wall as in our photos, sometimes your water supply comes up through the bottom of the vanity. In this case, you’ll have to shut off the main water supply and remove the shutoff valves so you can lift the old vanity away from the pipes. When you install your new vanity later, just cut matching holes in the bottom to make way for the pipes and then install new shutoff valves once the new vanity is in place.
With the plumbing unhooked, see how your vanity top is fastened. If it’s a one-piece cultured top or solid-surface, stone-like top, it’s probably secured with a bead of silicone caulk. You can usually pry it loose a bit and slip a keyhole saw between the vanity and top and cut away the adhesive. If you have a tiled top (Photo 4), there could be nails driven from the top into the vanity underneath the tile. These will usually come free with a pry bar. If you have a plastic laminate top, it could be fastened to the vanity with screws or caulk. Look for screws along the top edge of the vanity and remove them with a screw gun. If it seems nearly impossible to get the top free from the old vanity, you may have to take the whole thing out in one piece. This makes the job tougher, but with some clever maneuvering, you’ll be able to pull it free.
Fix up and paint your wall before you install the new vanity
Photo 7: Clean up the wall
Scrape away any glue or caulk left on the wall with a sharp scraper. Be careful not to tear the drywall paper beyond the repair area. Remove any loose bits of paper.
Photo 8: Patch the wall
Patch any wall damage with successive coats of drywall compound. Use a lightweight setting-type compound to speed up the process so you’ll be able to sand and paint earlier. After the patch is dry, sand it smooth and even with the adjoining wall surface.
Photo 9: Prime and paint the wall
Prime the wall patch and then paint the wall. We primed the entire wall medium gray to prevent the light color from showing through our new dark color.
While it’s not impossible to paint after you install your new vanity and top, it’s sure a lot easier to do it beforehand. First remove any caulk residue and then patch any wall damage (Photos 7 and 8).You may need a couple of coats of drywall compound if you have deep repairs. Wait for the patch to dry completely and then sand it smooth with the surrounding wall. Next, you can spot-prime the repaired areas and paint the entire wall. If you’re applying a darker paint over a light color as we did, prime all the drywall with a medium gray primer first (ask for this from your paint supplier) so you’ll get good coverage with the new paint (Photo 9).
Lay out your vanity dimensions on the wall
Photo 10: Mark the wall
Mark the locations of the new cabinets on the wall. We shifted our new cabinet assembly layout 3/8 in. to the left to meet the ceramic tile floor edge and also to keep the new countertop/sink from hanging over the cabinets farther than about 5/8 in.
Photo 11: Install the filler strip
Nail the filler strip to the side of the cabinet that meets the wall. Filler strips may be necessary to give your cabinet doors room to swing without rubbing against the wall. You may need to taper the filler strip for a tight fit. Also, build up the floor with wood strips nailed flush to the finished floor to help with leveling and make small positioning adjustments.
If your finished flooring doesn’t continue under the vanity, it’s best to lay out your vanity dimensions on the wall to help position it accurately. Measuring vanity cabinets can be tricky, especially if you have a multiple-piece vanity like ours. Just measuring the backs of the cabinets won’t do. If the cabinet has a face frame, the rear width of each cabinet is about 1/2 in. narrower than the front width because the face frame sticks out beyond the side panels about 1/4 in. on each side. Keep this in mind when you add up the dimensions for multiple cabinets. We ordered a filler strip to install on the right side of our cabinet where it met the wall. We also allowed for this extra width when we ordered our vanity top. These strips are typically 3 in. wide, so we ripped the strip to 3/8 in. wide and nailed it (Photo 11) to the edge of our first cabinet that adjoined the wall. This shifted the layout to the left just far enough to cover the edge of the old floor and meet our tile baseboard. Doing this also gave us a nice, comfortable overhang for the vanity top on the left side of the completed cabinet. Adding a 3/8-in. filler strip also allows room for a standard vanity top (3/8-in. overhang).
Remember, you can also hide small problems where the vanity meets the floor by adding a molding strip to the edge. You’ll also notice in Photo 11 that we built up the floor underneath the vanity with strips of plywood so the vanity would be flush with the level of the floor. Building up the floor does two things: It allows you to slide the vanity into position without its falling into the old recess, and it keeps it up slightly so you don’t lose height (an inch can make a difference to your lower back).
Mark the stud layout before you fasten your vanity to the wall
Photo 12: Screw the frames together
Screw the cabinet frames together before screwing them to the walls. Flush the fronts, clamp them, drill a clearance and pilot hole, then drive a screw near the top, middle and bottom of the cabinets. Evenly space the cabinet sides and shim them near the back and screw them together near the back edge. Cut protruding shims flush after you screw the cabinets to the wall.
Close-up of screwing frames together
Photo 13: Screw cabinet to the wall
Level the cabinets side-to-side and back-to-front using tapered shims and then screw them to the wall into the studs you located earlier. If your cabinet has a continuous panel along the entire back, cut away a portion to get at the plumbing. Use screw lengths that penetrate no more than 1 in. into the stud.
Photo 14: Install the kick panel
Cut the kick panel to fit and then nail it to the cabinet. Notch the panel to fit around the base trim. Add spacers behind the kick panel if necessary to cover any flooring problems in front of the cabinets
Close-up of notching panel for tile base
Notch the panel to fit around the base trim.
Screw your cabinets together before you fasten them to the walls (Photo 12). Slide them into position and use a level to make sure they’re level from front to back (Photo 13).You may need to use a tapered wood shim at the wall or floor to get it just right before you screw the cabinets to the walls. Align the cabinets with the level line you made on the back wall earlier. Be sure you’re sending your mounting screws into the studs. A missed screw into a water pipe at this point will add tons of time to your project!
Next fit the finished kick panel to the front of the cabinet. The kick panel is usually cut extra long, so you’ll have room to scribe it as we did (Photo 14) to fit against the tile base. If you need to cover a bit more flooring in front of the kick panel, shim behind the front panel with thin pieces of wood before you install the panel.
Install your faucets and drain assembly before you mount the top
Photo 15: Scribe the top to fit
Set the top onto the cabinet to check the fit. If an adjoining wall doesn’t allow you to set the top flush, you may need to scribe it to fit. We needed to remove a small portion from the front to allow the backsplash to fit into the corner.
Photo 16: Sand to the scribe
Sand to the scribe line with a coarse 80-grit belt in a belt sander and then check the fit.
Photo 17: Install the faucet and drain
Install the faucets and the drain assembly on the sink top before installing the top. Follow the directions that come with your new faucet and drain.
Photo 18: Install the top
Apply a 3/8-in. bead of silicone caulk to the cabinet top as shown. Set the top onto the cabinets with the faucet and drain assembly in place. Get help with this part of the job to avoid marring the walls or breaking the top. Install side splashes (Photo 20) against adjoining walls with silicone caulk at this time.
Photo 19: Connect the water supply lines
Connect the faucet supply tubes to the water supply and reconnect the trap. Braided flexible supply tubes make the connections easier. Loop, but don’t kink the lines. You’ll need to buy new washers for your trap and may need to trim pipe lengths to get everything to fit. You may also need a tailpiece extension if your new vanity is higher than the old one. Turn on the water and check for leaks.
Water supply connectors
Braided flexible supply hoses make the connections easier and are less likely to leak over time.
Photo 20: Apply caulk
Caulk where the backsplash meets the wall with siliconized acrylic caulk and smooth the joint with a moist finger. Let the caulk dry and you’re ready to use your new sink and vanity.
Before I mount and permanently fasten the sink top, I like to set it onto the vanity and dry-fit it to the walls. Our side wall wasn’t quite 90 degrees to the back wall, so we had to sand (Photo 16) a little off the edge of the top to get it to fit tight into the corner. (Cutting a solid-surface top like ours can void your warranty, but minor sanding on one edge like we did won’t damage anything.) Be sure to install your overflow tube (Photo 19) if you have a special molded sink. Follow the manufacturer’s instructions.
Now you can attach the faucets and drain assembly to the sink. Read your manufacturer’s instructions carefully. The biggest mistake installers make is tightening retaining nuts too tightly, which can crack the sink. Be sure to attach your supply tubes to the faucet before you set the top onto the vanity because it’s really hard to fit your hand—let alone a wrench— underneath to install the faucet later. Now you’re ready to set the top onto the vanity. First, apply a bead of silicone caulk to the topside of the vanity along the front and sides. Get someone to help you lift the top and gently drop it onto the cabinet. You’ll need to lift it high enough to allow the drain assembly to clear the cabinet. Ease it down and slide it into position. Connect the drain to the trap (use a new trap if necessary, and if you stuffed the drain line with a wet rag, pull it out first). Next, thread the new supply lines to the shutoff valves. We used braided stainless flex supply lines because they’re easy to apply and maneuver. Don’t overtighten them. Get them hand-tight and then use a wrench for a final half turn. Now look back up at your top to make sure it didn’t slide out of position while you were hooking up the plumbing. If it shifted slightly, nudge it back into position.
To finish the job, add your side splash panel along the adjoining wall (Photo 20) and run a smooth bead of caulk along the backsplash. To prevent shifting, let the caulk set for a couple of hours before using the sink. That’s it.
Required Tools for this Project
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
- Adjustable wrench
- Belt sander
- Circular saw
- Countersink drill bit
- Paint roller
- Paint scraper
- Paint tray
- Pry bar
- Safety glasses
- Sanding block
- Screw gun
- Scribing tool
- Stud finder
- Table saw
- Utility knife
- Wrench set
Required Materials for this Project
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.
- 80-grit sandpaper
- braided stainless steel supply hoses
- Drywall compound
- faucet and drain assembly
- Plumber's putty
- Silicone caulk