How to Install a Bathroom Vanity

A new vanity is the highest-impact bathroom upgrade for the money. Plumbing prep matters more than the cabinet install itself.

Shut off both angle stops, disconnect supply lines, and loosen the P-trap into a bucket. Remove the old vanity by cutting any caulk at the wall and floor with a utility knife, then sliding the cabinet free. If the wall behind it is damaged, repair it before the new vanity goes in — once the cabinet is set, you can't reach back there.

Dry-fit the new vanity to mark where the supply lines and drain pass through the back. Cut clean holes with a hole saw — slightly oversized for adjustment. Slide the vanity into place, shim it level on all four corners, and screw through the back rail into wall studs (two 3" screws per stud).

Set the top in a continuous bead of construction adhesive on the cabinet rails. Connect supply lines with new braided stainless flex connectors (don't reuse old ones), and rebuild the P-trap from the trap arm at the wall out to the sink tailpiece. Standard slip-joint nuts; hand-tight plus a quarter turn.

Run water and check every joint with a dry paper towel — drips show up immediately on paper. Caulk the gap between vanity top and wall last. Total job runs 3–5 hours for a single-sink, longer for double or for old galvanized supplies that need replacing.