How to Install a Floating Bathroom Vanity

Installing a floating bathroom vanity involves securing wall support, mounting brackets, ensuring perfect leveling, hanging the cabinet, and connecting plumbing. 

When I installed my small floating vanity without drawers, it took me about 8 to 10 hours spread across two days. For more complex floating bathroom vanity installations, I’d suggest planning for a full weekend (or more) to avoid rushing through this project. Remember, this isn’t a beginner’s project. You’ll need some DIY experience and definitely a helper. 

Tools and Materials List

Required Tools

• Pencil
• Safety glasses
• Work gloves
• Dust mask
• Level (2-foot and 4-foot)
• Tape measure
• Electronic stud finder
• Circular saw
• Drill and drill bits
• Basin wrench
• Adjustable wrench
• Pliers
• Utility knife
• Flashlight

Required Materials

• Vanity (Cabinet, sink, faucet)
• 2×6 lumber for bracing (Optional)
• Silicone caulk
• Construction adhesive
• 3½-inch construction screws
• Heavy-duty mounting brackets
• 5/16-inch lag screws with washers
• Drywall repair materials
• Joint compound
• Rubbing alcohol (for sink installation)
• Cardboard (for protecting the countertop)
• Mounting clips (only for under-mount sinks)

Step 1: Find the Instructions

Before doing anything, make sure to check out the manual that comes with your bathroom vanity. It’s essential because every vanity is a bit different, and you’ll need to get to know yours before getting started.

Step 2: Planning

Chances are you’re replacing an existing vanity – ignore this step if you aren’t. If so, disconnect your previous unit from the plumbing system and carefully take it out of place.

Then, switch off the water supply and clean the area thoroughly.

Step 3: Check Your Plumbing Height

Before deciding on your vanity height, look at your drain pipe location. Your floating vanity probably has pre-cut holes and drawer cutouts made to fit around the drain trap. This means you’ll need to position your vanity where it works with your existing plumbing, not the other way around.

Take a good look at your vanity’s back panel and drawers. Find the cutouts meant for plumbing. Now, check if these will line up with your wall pipes. 

If they don’t match, you have three options:

• Move your vanity slightly up or down (while keeping the top at a comfortable height)
• Call a plumber to move the pipes (this can be expensive)
• As a last resort, modify the vanity’s back panel (though this isn’t ideal)

Step 4: Measure and Mark

Most bathroom vanities end up at 34½ inches high – this is the standard height for most floating vanities. But since you might add a countertop later (it’s usually around  ¾ inch thick), you’ll need to subtract that first.

Measure up from your floor 33¾ and make a small mark. Now, move over about a foot and make another mark at the same height. Keep doing this across your wall, going about 6 inches past where your vanity will end on both sides.

Next, place your level against these marks and draw one clean horizontal (side to side) line. This line shows where the top of your vanity cabinet sits.

My Tip: Vanity height is flexible. For example, my husband is a tall man, standing at around 6 feet 3 inches. So, I installed our floating vanity at 36 inches to better suit his needs. Generally, your goal should be to achieve a final height between 32 and 36 inches.

Step 5: Finding Wall Studs

The floating bathroom vanity needs to be attached to solid wall studs for reliable support. So, run your electronic stud finder tool slowly across the wall and mark any beeps with a pencil dot along the level line you drew earlier. 

Bathroom walls hide studs, electrical wires, and plumbing pipes. If this is your first install in this spot, double-check everything before drilling: 

• Check if the marked spot is 1½ inches wide (that’s a stud’s width)
• Measure intervals – studs appear every 16 or 24 inches, while pipes often break this pattern
• Tap the wall lightly – studs sound solid, pipes sound hollow

Need more info on wall studs, like what they are, how far apart they usually stand, or how to spot them without an electronic stud finder? Check out our guides:

• How Far Apart Are Studs? 
• How to Find Studs Without a Stud Finder (A Beginner’s Guide) 
• Different Types of Wall Studs: Pros and Cons of Each 
• What is a Stud in a Wall? 

Step 6: Add Blocking Between Studs (If Needed)

Your floating bathroom vanity will need at least three solid mounting points, each 16 to 34 inches apart. When enough studs aren’t available, I strongly recommend opening the wall to add blocking between studs for extra support, especially if your vanity’s on the heavier side. 

First, mark a rectangle between studs where your vanity will hang, about 12 inches tall. Use your utility knife to score the drywall along these lines. Cut slowly through the drywall – no need to rush. Pull the drywall piece out carefully. Next, add horizontal 2x6s between the studs.

Here’s how:

• Measure between studs twice
• Cut your 2×6 board to fit snugly between studs
• Spread construction adhesive where the board meets the studs
• Secure the board with 3-inch deck screws – use two screws on each end where it meets the studs
• Put the drywall piece back and patch it with joint compound
• Let it dry completely (24 hours) – rushing this part will only cause problems later

My Tip: Even if you feel confident now about where your vanity should be, I suggest giving step 3 another whirl. Cutting into the wall could have erased your first marks for height, and you want those bracket positions to be spot on.

Step 7: Install the Mounting Brackets

Check your vanity box – the brackets should be in there. If they’re missing, you’ll need to buy some that can handle your vanity’s weight.

Here’s what to do:

• Use a pencil to mark where the brackets will go based on your earlier measurements.
• Use a drill to make pilot holes at these marks. This keeps the wood from splitting when you add screws.
• Before attaching, hold each bracket against the wall and check that it’s perfectly level. This step is important for a stable vanity.
• Use long lag screws with washers to attach brackets to the studs.

My Tip: Double-check that everything is level before screwing in fully. If something feels off, it’s okay to adjust and try again.

Step 8: Attach the Vanity Cabinet

Attaching the vanity isn’t a one-person job. Even if it’s small and doesn’t have drawers, like mine, you’ll need someone to help you lift it. My husband helped me, and it made things way easier. 

If your vanity has drawers, take them out first. It makes the cabinet lighter and lets you see where to attach it better. 

Here’s what to do: 

• With your helper, carefully lift and align it with the marks on the wall.
• Use buckets or wood blocks underneath to hold it steady while working. 
• Start by putting screws into the top holes first. This helps hold most of the weight. 
• Use a level to make sure everything is straight. 

Once everything is secure, put any drawers back in place and make sure they open and close smoothly. If anything feels loose, double-check your work before moving on.

Step 9: Install the Countertop

If you’re using a countertop, this is the time to place it on top. You might need an extra pair of hands for support.

Here’s what to do:

• Clean the top of the vanity really good
• Put a line of silicone caulk around the top edge of the vanity
• Place the countertop carefully on top
• Let it dry before doing anything else (about 24 hours)

Step 10: Faucet Installation

Place cardboard on your vanity top to protect it and gather your tools: an adjustable wrench, a basin wrench, a flashlight, and cleaning supplies.

Some faucets are mounted directly to the countertop, like mine, or need installation on the sink. It really depends on the faucet design you’ve chosen. However, in both cases, your sink will have holes to accommodate this.

Here’s what to do:

• Turn off the water supply valves completely
• Check if your faucet includes rubber gaskets (the black rubber rings that create watertight seals) or O-rings
• Place the rubber gasket or O-rings  (which act as a waterproof cushion) between the faucet and countertop.
• Make sure hot water is on the left side.
• Insert faucet through mounting holes
• Hand-tighten mounting nuts – the large nuts that secure the faucet from underneath
• Use basin wrench for final tightening – careful not to overtighten

Step 11: Sink Installation

Most floating vanities include a pre-cut sink opening on top for nesting the sink.  But some designs specially cater to vessel sinks – like mine, with just a drain hole in place.

Remember, your sink comes with its own installation manual, so make sure to carefully follow the instructions that come with it.

Here’s how I installed my vessel sink:

• Clean all surfaces thoroughly with rubbing alcohol
• Apply a continuous bead of 100% silicone (creates a waterproof seal) around the bottom edge of the sink
• Apply silicone around the drain opening
• Center your sink carefully over the drain hole
• Press down evenly all around and hold for about 30 seconds
• Immediately wipe away excess silicone with a damp cloth before it dries
• Let the silicone cure for 24 hours before connecting the plumbing

My Tip: For under-mount sinks, the process is usually similar, but you’ll need mounting clips (included with the sink). After cleaning surfaces and applying silicone to the sink’s rim, I would suggest having someone help hold the sink while you secure the clips from underneath. 

Step 12: Connect Plumbing

Now that your sink and faucet are set, it’s time to connect the pipes that make everything work.

Grab your pliers and wrench and start with the P-trap (that curved pipe under the sink). Line it up with your wall drain pipe – it should slope slightly downward (about 1/4 inch per foot) toward the wall.  Then, check that all washers are in place and facing the right way.

Hand-tighten everything first, then use pliers to give each connection a final quarter turn – but don’t overdo it.

For the water lines:

• Connect the flexible water supply lines to the shut-off valves
• Remember: hot water goes on the left
• Keep the lines straight without any twists
• Hand-tighten first, then use a wrench to secure, just a little past hand-tight

My Tip: Before testing, I suggest removing the faucet aerator (the screen at the faucet tip) to prevent clogging from initial debris. Turn the water on slowly and check all connections for leaks. Once you’re sure everything’s dry, put the aerator back on. 

Step 13: Final Touches

Now that most of the work is done, check if everything is still level and lined up properly. If you removed any drawers, put them back in and make sure they slide smoothly.

When I installed my vanity, I wiped everything down at the end to clear off dust and fingerprints. It made everything look nice and clean after all the hard work.

My Tip: Wait a full day before using the sink normally – this gives the seal time to dry properly.

Enjoy Your New Vanity

Installing my small floating bathroom vanity challenged me, but the feeling of success was great. 

My advice: take your time, don’t rush through the steps, and definitely ask for a friend’s help. It makes things much easier and more fun. With patience and attention to detail, your new floating vanity will be up in no time. 

See Related:

• The 7 Best Materials for a Bathroom Vanity Countertop 
• Types of Bathroom Vanities to Consider for Your Home
• The Pros and Cons of a Floating Bathroom Vanity

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