A pedestal sink brings a clean, open look to a bathroom because it removes the vanity cabinet entirely. The design is simple: an upper basin holds the fixtures, and a hollow pedestal stem rises from the floor to hide the water supply lines and the drain pipe. Installing one takes two to four hours of hands-on work spread over one to two days, with a typical project cost of $150 to $300 for the sink and materials. The skill level is intermediate, mostly because the basin has to be supported by the wall rather than by a cabinet frame. If you are outfitting a tight space such as a powder room or a laundry corner, the same approach used for installing a compact utility sink applies, since both jobs hinge on accurate rough-in measurements and solid wall anchoring.
Three conditions have to be in place before the new sink goes in: the bathroom floor must be fully installed and finished, the wall behind the sink must be built and painted, and the drain and water supply lines must already be stubbed out of the wall at the right heights. Installing the sink before those are done forces you to cut into finished surfaces and redo work. Plan for the rear wall mounting plate as well, because the pedestal alone does not carry the basin safely.
Plan the Job: Measurements, Tools, and Materials
Start by recording three numbers: the distance between the supply stubs, the height of the drain opening, and the desired finished height of the basin rim. Most pedestal sinks put the rim between 32 and 34 inches above the finished floor, with supply stubs roughly 20 to 22 inches up and the drain center about 18 to 20 inches up. Compare those figures against the sink’s own dimensions before you buy, because manufacturers vary.
Check the Rough-In and the Room
The pedestal footprint is small, usually no more than 10 to 12 inches deep, which is what frees up floor area. That also means there is no storage below the basin, so confirm the room has a cabinet or shelf elsewhere for toiletries. The wall must be finished and painted before the sink goes up, since cutting into it afterward means repainting the patch.
Three prerequisites before you start
- Flooring fully installed and finished
- Wall behind the sink built and painted
- Drain and water supply lines stubbed out in the wall
Tools and Materials for the Job
Gather the tools before opening the wall: an electric multi-tool for cutting drywall, an electric drill, a saw, a tape measure, a bubble level, a pencil, a stud finder, a drywall knife, and a ratchet wrench set. A bar clamp is a useful extra. When you work alone, clamping the basin in position while you drive the mounting screws gives you a third hand, the same trick described for installing an undermount sink with a bar clamp.
| Material | Role in the installation | Typical quantity |
|---|---|---|
| Pedestal sink kit | Basin, pedestal stem, and wall-mounting hardware | 1 complete set |
| Two-by-six board, 4 ft | Wall backing between studs for the mounting plate | 1 board |
| Scrap drywall | Patch for the backing opening | As needed |
| 3-inch wood screws | Backing and bracket to the studs | 4 to 6 |
| 1-1/2-inch drywall screws | Drywall patch | 12 to 20 |
| Joint compound and paper tape | Seam the patch before painting | 1 tub, 1 roll |
Buy the two-by-six a foot longer than the expected stud spacing so you can cut it to fit on site. Standard framing places studs 16 inches on center, which leaves a 14-1/2-inch gap for the backing board. The extra length also lets you square the ends against the stud faces without a second trip to the saw.
Shut Off Services and Open the Wall
Before any cutting, turn off the water and the electricity. Shut the supply valves on the two lines feeding the old sink, or close the main shutoff if the room has none. Cut the circuit that feeds the wall behind the sink, because you will be cutting into that wall and driving screws near wiring. For a photo-by-photo version of the full procedure, the pedestal sink installation guide from This Old House walks through the same sequence.
Shutoff Sequence
Water and power shutoff order
- Close the supply valves or the main water shutoff
- Open the old faucet to drain residual water from the lines
- Switch off the circuit breaker for the wall and verify with a tester
If a vanity or old sink is already in place, disconnect the supply tubes, loosen the P-trap slip nuts, and lift the old unit out before you open the wall. Protect the floor with drop cloths and set the old fixture aside for disposal. Removing the old fixture first keeps the work area clear and exposes the rough-in stubs you need to measure.
Cut the Opening and Mark the Studs
Run the stud finder across the wall and mark the centers of the studs nearest the sink location. The mounting bracket will land on the backing board you install between two studs, so the stud positions determine where the bracket goes. Use the multi-tool or a drywall knife to cut a clean opening big enough to work the backing into place, and save the cutout piece to patch the hole later.
Build the Rear Wall Mounting Support
The pedestal hides the plumbing, but it does not carry the basin. The basin hangs from a mounting plate screwed to the wall, which is why manufacturers include a rear wall mounting plate and why that plate has to anchor into solid framing rather than drywall alone. Skipping this step leaves the basin relying on the pedestal for support, and a shifting pedestal can push the sink out of level.
Frame the Backing Board
- Cut the two-by-six to span the gap between the two marked studs
- Hold it at the height that lines up with the basin mounting holes
- Screw it to the studs with 3-inch wood screws
- Patch the opening with the saved drywall piece and paper tape
Set the Mounting Plate
After the compound dries, hold the mounting plate against the wall at the marked height and confirm it with a bubble level. Drill pilot holes through the plate into the backing, then drive the screws that came with the kit. The plate must sit perfectly level, because the basin rim will follow it.
Patch and Paint the Wall
Apply joint compound over the taped seams, let it dry, sand, and paint the patched area to match the wall. Do this before the sink goes up, because touching up behind a mounted basin is awkward.
Hang the Basin and Connect the Drain
With the mounting plate in place, lift the basin onto the plate and seat it against the wall. The basin holes should line up with the plate slots. If they do not, recheck the plate height before drilling anything.
Level and Secure the Basin
Securing sequence
- Set the basin on the mounting plate
- Place the bubble level across the rim and adjust
- Mark the screw locations through the plate slots
- Drive the mounting screws until the basin is snug
Connect the Drain, Trap, and Supply Lines
Slip the drain tailpiece into the drain stub, then assemble the P-trap with the slip nuts hand-tightened first and snugged with a wrench. Connect the two supply tubes to the shutoff valves and tighten the compression fittings. If the drain trim is old, swap the stopper mechanism while the basin is empty, since replacing a pedestal sink pop-up assembly is far easier before water runs through the trap.
The tailpiece may need trimming to reach the drain stub. Measure twice, mark the tailpiece, and cut it with a hacksaw or the multi-tool; most kits allow a 1- to 2-inch adjustment through the trap arm.
Set the Pedestal and Finish the Fit
Slide the pedestal stem under the basin and align it with the drain trap. The stem hides the trap and the supply lines, so route them neatly before the pedestal goes in. Shim the base if the floor is not perfectly flat, then mark and drill the floor anchors that came with the kit.
Align the Pedestal to the Basin
The top of the stem should meet the underside of the basin with no visible gap. If the gap is uneven, adjust the basin on the mounting plate before tightening the floor anchors. When the room is a primary bathroom used every day, the pedestal choice deserves extra thought about basin depth and counter space, and the guidance on pedestal sink selection for primary bathroom designs covers those sizing and finish decisions.
Seal the Seams
Run a thin bead of silicone caulk where the pedestal meets the floor and where the basin meets the wall. Smooth it with a wet finger and wipe the excess before it cures. Caulking keeps water from wicking behind the sink and makes future cleanup easier.
Test the Installation and Plan the Next Project
Turn the supply valves back on and check every joint you touched. Run water for a few minutes, then dry the fittings with a paper towel and watch for drips.
Leak-Test Checklist
- Supply tube nuts at the shutoff valves
- Compression fittings under the basin
- P-trap slip joints
- Drain flange where it meets the basin
- No drips after 10 minutes of running water
Related Bathroom Upgrades
If the remodel continues, the sealing and fit-up techniques used for installing an undermount sink with countertop prep carry over to other fixtures, because they rely on the same silicone bead and shim logic.
When the walls are ready for decoration, a tile mural on the shower wall finishes the room with a decorative feature that takes up no floor space.