How to Install a Bathroom Vanity

Every bathroom should have a vanity complete with a sink, soap, and towel. Sometimes the trick is how to get them installed and working.

Installing a new vanity is usually not very difficult. Especially if you are replacing an existing one. Take good note of the plumbing attachments and the size of the cabinet–then match them with the new vanity and sink(s).

Although changing the vanity is a big upgrade to your bathroom, give some serious consideration to doing more upgrades while you have the room partially torn apart.

Here is what you need to know to get the old vanity out and the new vanity in.


It’s Time to Replace Your Vanity When . . .

Your Plumbing Leaks

Water leaking in and around your vanity can cause permanent damage to your vanity.

  • Swollen or Warped Cabinet. Most vanity cabinets are made of Medium Density Fiberboard (MDF)–a combination of sawdust and glue. It absorbs water like a sponge. Swells and stays swollen even if it dries out.
  • Mold Growth. Mold can start to grow in 24 hours. Black mold is not only unsightly, it can cause allergic reactions and even asthma attacks.
  • Odor. Mold stinks.
  • Floor/Wall Damage. Enough water getting onto or into the floor and/or walls will damage the subfloor, drywall, and insulation batts (if they are in the wall).

It is Chipped, Cracked, Scratched, Dented, etc.

Vanities are used every day–sometimes by many people. Cracks, chips, scratches, and dents appear. And get worse. Besides being unsightly, cracked and chipped vanity tops let water get to the MDF.

You are Moving

Many people spruce up their homes before moving. Bathrooms are one of the more important rooms when selling. Bathroom renovations have a 67% Return on Investment (ROI).

Better Use of Space

If I changed vanities in both our bathrooms I could add 6 inches in width, built-in medicine cabinets, and shelving above the toilets. Most people can apply a little creativity to their bathrooms when changing vanities.

You Just Don’t Like it Any More

Styles change. Fashions change. People’s tastes change. Your vanity and/or bathroom may have passed its “Best Before” date. And you are just done with it.

Choosing the New Vanity

Vanity Cost

Cost is usually one of the main factors when choosing a new vanity. And they vary greatly. Vanities start around $300.00 and can end up costing over $3000.00. They may have sinks and faucets included. 

Vanity Size

Standard vanities are around 32 “ high and 20” deep. Widths vary from 24’ to 72”. Generally, you are removing a standard-sized vanity. Replacing it with another one should be easy. 

A good cabinet shop or carpenter should be able to customize your vanity to fit your needs. If you are ordering custom vanities, take pictures and exact measurements. You really want it to fit when it arrives.

Vanity Material

Most vanity cabinets sold today are manufactured of MDF with melamine laminated onto the panels. Melamine laminate is available in dozens of colors and woodgrain-appearing finishes. 

Vanity tops are available in laminate, granite, corian, quartz, and wood among other options. Colors and designs are almost unlimited. Sinks and taps are also available in multiple styles and colors.

Bathroom Layout

Unless you are doing a major bathroom renovation, the type and style of your new vanity depends on the existing bathroom design. Generally, there is a finite amount of space available for the vanity. And that is where the plumbing is.

Vanity Style

Modern vanity styles depend more on feet. Older vanities were almost all boxes. Pulling out the old box vanity may provide surprises. The flooring may not go all the way under the old vanity. Or you may find a godawful heat vent hole. Knowing what is under the old unit before ordering a new one may save a lot of work. Buying a full-box unit could be a better option.

If you have the space and desire you can plan a two-sink vanity. If you plan on remodeling the entire bathroom in the future, put in the style of vanity that will fit well with the finished room.

Replacing the Bathroom Vanity

If you measured and ordered properly, replacing your vanity, sink, and taps is fairly straightforward. Remove the existing unit, take measurements and note of how it is all attached, and install the new unit–attaching plumbing the same way you removed it. 

Equipment You Need

  • Bucket and towels
  • Painter’s tape and window shims
  • Drill c/w multiple screwdriver ends
  • Hole saws and/or spade bits to drill holes for plumbing. Maybe a jigsaw
  • 18” Wonderbar
  • 8” Glazing bar
  • Tape measure
  • Adjustable wrench
  • Plumbing pliers
  • Drywall screws, spackle. Maybe a little drywall if the wall needs to be repaired.
  • Stud Finder
  • 2’ Level
  • Tub and tile Silicone caulking and caulking gun
  • Vanity c/w countertop and sink

How to Replace the Vanity

  1. Turn off the water supply. Cover the bottom of your old vanity with a towel and place the bucket under the plumbing.
  2. Disconnect the water supply from the taps. Disconnect the drain and P-trap. You should be able to empty most of the water into the pail, but be prepared to get a little wet. Remove the heat vent cover from the front of the vanity box–if there is one.
  3. Tape the drain pipe closed with painter’s tape. Unless you enjoy the smell of sewer gas.
  4. Remove the old vanity. Note: You may have to enlarge the water line holes and/or the drain holes to get the vanity out. (Quite often water lines are run into the cabinet through 1” holes. Then shut-off taps are installed.)
  5. Note: Before installing the new vanity, check for wet or soft drywall. Replace any you find. Patch any holes in the drywall. Use a stud finder to locate and mark wall studs.
  6. Drill all the plumbing holes where required. Cut out the bottom face of the box (if required) for the heat vent.
  7. Install your vanity level, plumb, and square. Use window shims as required between vanity and wall, and vanity and floor as required. Screw the vanity box to the back wall. Make sure you hit the studs you marked.
  8. Install the vanity top. Screws or brackets should be supplied by the manufacturer. Use the template and jigsaw to cut out the sink hole. Install the sink and taps. Note: If you are certain of your measurements, install the sink and taps before placing the vanity top on the box. 
  9. Note: Many countertops are manufactured with the sink as part of it. If you purchased this type of unit, just install the taps before installing the top. You will not have any choice of positioning.
  10. Attach all of the plumbing, turn the water back on, and check for leaks.
  11. Install the backsplash–usually with glue like No More Nails. Use silicone caulking to seal the backsplash to the wall and vanity top, sink to the top, and vanity box to the wall.

Call a Professional

Many people do not feel comfortable taking on this type of plumbing related project. Hiring a professional to install your vanity will add anywhere between $100.00 and $1000.00 to the project depending on the complexity. Advantages to hiring a contractor include:

  • Knowledge. Experienced plumbers will be a great help when you are choosing your vanity and fixtures.
  • Quick. Especially if it is your only bathroom, you want it working quickly.
  • Warranty. If anything goes wrong, you have someone to call for repairs.

Make sure you get 3 quotes before deciding on who to hire.

How to Install a Bathroom Vanity
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