Replacing a Pedestal Sink

There’s an elegance to pedestal sinks. When placed in a small bathroom they can give the bathroom a larger feel due to their small footprint. If you have a wood vanity and want to replace it with a pedestal sink you should hire a licensed plumber.

The location of the drain and water supply lines is commonly lower than what you’ll need for a pedestal sink. If so, you’ll need to open up the wall to replace the plumbing. Also you’ll need to install blocking between studs that the sink will screw into. This could take days plus the wall will need to be re-finished before installing the new sink.

Replacing a pedestal sink can still be a challenging DYI project. Allow one full day to complete. TIP: before you buy your new sink measure the distance from the floor to the bottom of the P-trap and elbow assembly (lowest point). Why? The back of some pedestals are different. Knowing the room you’ll need could save time and money.

If you’re going to use the same faucet make sure you buy a sink with the proper spacing, sinks come in two opening configurations, 4”-8”, the distance for the faucet supply lines. Now that we’ve addressed the above let’s get started.

Tools & Materials: Plumber’s putty and tape, level, crescent wrench, hacksaw (if neede), tape measure, screwdriver, pliers. Skill Level
One hammer: Novice
Five hammers: Experienced

BEFORE
This sink was replaced because it had cracks in the basin and the homeowner didn’t like the style. AFTER

STEP 1 -Turn off both water supply lines.

STEP 2 -Disconnect both water supply lines.

Place towels on the floor to catch water still in the lines and drain.

Step 3 - Disconnect the P-trap at the wall.

You might need pliers for this step. Leave the faucet and drain pipes attached they’re easier to remove when the sink is on the floor. Step 4
Remove the anchors that hold the sink to the wall. You might need a wrench for this depending on what was used to hold the sink to the wall.

Step 5 - With all the connections loosened remove the sink.

You’ll need a helper to hold the sink base as you work the P-trap from the wall. There’s a good chance that the location of the mounting bolts that held your old sink will not match up with the new sink. Remove them at this step.

Step 6 - Remove the P-trap and elbow from the sink.

At this point if you’re going to re-use the same hardware you can clean out the pipes before installing them back in the new sink.

Step 7 - Remove the water supply lines, then remove the nuts holding the faucet to the sink.

Step 8 - Measure from a doorjamb or the end of the wall to the center of the drain.

Mark that distance on the floor to center the pedestal. Dry-fit both new sink pieces against the wall to locate the distance from the wall to the front of the pedestal. Mark this dimension on the floor and pedestal as a reference when placing the new sink when you’re ready to mount and level the sink.

Step 9 - It could be easier to place the P-trap and elbow in place but not tighten before installing the new sink.

If you’re not re-using the old drain you’ll need to measure and cut the new drain to match where the elbow is located. Use pipe dope or plumber’s tape to reconnect to all male connections on the drain.

Install the faucet to the new sink in reverse steps when you disassembled it from the old sink. Some faucets are sealed and do not need plumber’s putty and some need putty. Read the instructions that came with the new faucet. Although you will need to use putty to install the pop-up drain. Roll a wad of plumber’s putty into a 3/4” wide sausage and wrap it around the pop-up drain, underneath its flange. Place the drain into the basin hole, from under the basin hand tighten the gasket and washer onto the drain. Finish tightening with pliers a quarter turn, remove the extra putty with your finger and clean any residue with a paper towel or sponge.

Step 10 - Place the basin on the pedestal and against the wall.

Use your helper for this and the next step. Fine tune the pedestal and level the basin side-to-side. You might need to shim the pedestal due to the floor not being level, use a wood shim to level the basin and break off the extra wood. Or you can use any hard material, but place it from the inside of the pedestal so you can’t see it from the outside.

Step 11 - Mark the location of the new mounting holes and remove the sink.

Test with a nail to locate the mounting block. If the new mounting location misses the mounting block from the old sink you can use hollow wall anchors (see the anchoring story from the Feb/Mar 2003 issue of Northwest Renovation magazine or log on to www.nwrenovation.com and go to the archive page). Connect the sink to the wall. Use shims again if needed and check for level. Some pedestals can be mounted to the floor, if so do that now.

Step 12 - Connect and tighten the water supply and the P-trap (don’t overtighten).

Turn on the water and test for leaks, also close the stopper, fill the basin half full, and release to check for leaks in the drain system.

In conclusion there’s a few things to take into consideration. The water supply tubes that were mounted on the old sink might not match to the location of the new or old faucet. You can substitute them with a flexible hose. Measure the distance between the faucet and the water supply and add two inches and buy one that closely matches that length. Do not try to force the old rods into the new location you can crimp the rod and you’ll still have to buy new hoses. You’ll also need to run a bead of chalk where the sink back meets the wall. Use a bathroom caulk.