If you think that pedestal sinks are old-fashioned relics of Victorian plumbing, look again at some of the new models offered by contemporary designers. They present a refreshing alternative to the vanity mounted sinks found in most homes.
Before replacing an existing vanity with a pedestal sink, examine the present location of the plumbing connections (supply pipes and drain pipe). Installing the new sink will be relatively easy if these pipes do not have to be moved to accommodate the new fixture. If they do, you'll have to open up the wall to expose the pipes and refit them.First measure the height of the drain pipe; that is, the distance from the floor to the point where the pipe emerges from the wall. Then compare this measurement with the drain requirement on the new pedestal sink. If the measurements are only an inch or two apart, you will be able to install the pedestal sink with little or no problem. A wide gap between the measurements means that you'll have to move the drain. This can be a lot of work.
Next look at the supply lines. In most cases, there will be shut-off valves with flexible chrome-plated copper tubes, the risers, running up to the faucets. The new hook-up will only involve closing the valves and connecting new risers from the valves to the sink faucets. There will be more work, however, if you decide to relocate the shut-off valves so that they will be hidden by the bowl of the new sink. Then you will have to open up the wall and connect additional pipes to the existing lines.
If you decide to go ahead with the project, start by shutting off the water to vanity. Disconnect and remove the supply risers, drain pipe and trap. Then remove the vanity. The cabinet will most likely be screwed to the wall and possibly the floor also.
Most pedestal sinks are designed to be supported primarily by a hanger bracket mounted on a backer board. Even if you are not going to move the existing pipes, you'll still have to open up part of the wall to install the backer board. The backer board is a length of 2 by 8 that's attached to the wall studs.
Since the studs are 16 inches apart on center, the board should be about 18 inches long. The height of the backer board (that is from the floor) will be determined by the sink requirements.
To install the backer board, cut through the wallboard with a utility knife and a saw. The cutout must be large enough - about 9 by 19 inches - to accommodate the backer board and to expose the supporting wall studs. Use a handsaw to notch the front edges of the studs, and set the board into the notches. Use drywall screws to hold the board in place. Close up the wall with a new piece of wallboard. Then tape and spackle around the joints; sand the patch, then prime and paint the wall.
Next examine the floor. There may be a noticeable rectangle where the vanity stood. Try removing it by buffing the floor with a fine-grit steel wool pad. If this doesn't work, you'll have to replace the covering.
When the floor and wall are finished, you can begin installing the sink. First mount the hanger bracket on the wall. Use 1/4-inch diameter lag bolts to secure it to the backer board. Use a level to make sure the bracket is horizontal and level.
Next, attach the faucets to the sink. Mounting configurations can vary depending upon the faucet brand, but usually the faucets will have a threaded pipe, the tailpiece, that projects through a hole in the sink and is held in place with a washer and mounting nut.
Now you can lift the sink and hang it on the hanger bracket. A pedestal sink can be heavy, and while one person might be able lift it in place, it is much easier and safer to enlist the aid of a helper for this task. Be sure that the sink is secure on the hanger bracket, then hook up the drain pipes. The drain sections are held in place with slip nuts and washers. Next, attach the risers from the shutoff valves. These have compression fittings and are attached with compression nuts.
At this point, you can slide the pedestal into place. Place a sheet of cardboard under the pedestal base to keep it from scratching the floor as you maneuver it.
With most sinks, the pedestal is secured in place by bolting it to the floor. Check with the manufacturer's instructions for the size and positioning of the anchoring bolt. You will have to drill a pilot hole for the bolt.
Apply a bead of silicon caulk around the base and also around the edge of the sink where it contacts the wall.