Installing a bathroom vanity and sink is a rewarding DIY project that can refresh your space with added style and functionality. With the right preparation and tools, the whole job typically takes about 2–4 hours.
The key is to anticipate common quirks of real bathrooms – like slightly crooked walls, off-center plumbing, or stubborn shutoff valves – and plan around them. This guide will walk you through how to install a bathroom vanity and sink step by step, with tips to avoid surprises and ensure a professional result.
Step 1: Plan and Prepare
Check Shutoff Valves
Before starting, test your shutoff valves under the sink. Turn each valve off and open the faucet. The flow should stop completely.
- If water keeps running, the valve stem may be stripped or frozen.
- Shut off the home’s main valve and replace or cap any bad shutoffs before continuing.
A quick test now can prevent a flooded floor later.
Measure Key Dimensions
Accurate measurements ensure your new vanity fits both the wall and plumbing layout.
- Width: Measure wall-to-wall at floor level and again at 32–34 inches high.
- Drain Height: Note the height of the drain stub-out (standard: 16–20 inches from floor).
- Drain Offset: Measure from a side wall to the drain’s centerline.
- Supply Height & Spacing: Hot and cold lines typically sit 20–22 inches high and about 8 inches apart.
- Faucet Holes: Identify if your sink top uses single-hole, 4-inch centerset, or 8-inch widespread spacing. Match your faucet accordingly.
Gather Tools and Supplies
Tools: Level, tape measure, adjustable wrench, basin wrench, pliers, utility knife, stud finder, drill, hole saw, and caulk gun.
Materials:
- Shims and 2½″ cabinet screws for mounting
- 100% silicone caulk for wet seams and paintable latex caulk for trim
- Plumber’s tape, plumber’s putty or gasket, and a new P-trap kit
- Replacement supply lines if existing ones are too short or worn
For a smoother install, pick up all these items and compatible vanities, sinks, and faucets at Woodworker Express Bathroom Solutions.
Step 2: Remove the Old Vanity
- Shut off water and relieve pressure at the faucet.
- Disconnect supply lines from both the valves and faucet.
- Remove the P-trap and drain tailpiece over a bucket.
- Cut caulk lines at the wall, backsplash, and floor.
- Lift off the top carefully—porcelain or stone can crack.
- Unscrew cabinet mounts from studs.
- Pull the cabinet out slowly, guiding pipes through.
- Plug or cover open pipes to block sewer gases.
- Clean and patch walls so the new vanity sits flush.
Step 3: Install the New Vanity Cabinet
- Locate wall studs and mark their centers.
- Prep the cabinet: remove drawers, cut back holes if needed for plumbing.
- Set and align the cabinet against the wall.
- If baseboards interfere, notch the back or remove a section.
- Level and shim until the cabinet sits plumb in both directions.
- Secure to studs with cabinet screws through the upper back rail.
- Apply silicone around the cabinet rim, then lower the vanity top or sink in place.
- Wipe excess sealant and let it cure before connecting plumbing.
Step 4: Install the Bathroom Sink and Faucet
- Mount the faucet on the sink or top. Tighten all hardware and connect supply hoses.
- Install the drain assembly with plumber’s putty or the provided gasket under the flange.
- Connect the P-trap between the sink tailpiece and wall drain. Adjust as needed for alignment.
- Attach supply lines to the shutoff valves—hot on the left, cold on the right.
- Turn on water slowly and check every joint. Tighten fittings as needed to stop drips.
- Seal edges with silicone around the backsplash and sink rim.
Step 5: Final Checks: How to Install Bathroom Vanity and Sink
- Vanity is level and tight to the wall.
- Doors and drawers open freely.
- No leaks at valves, supply lines, or trap.
- Sink drains quickly without noise or backup.
Recheck for leaks after 24–48 hours of use. If you spot a drip at a valve or fitting, tighten slightly.
