With space at a premium in most bathrooms, the switch from cabinet-style to pedestal sink adds precious inches. Even if the location of the space is academic with respect to storage, the sleek lines and modern feel of a pedestal sink are well worth the time spent on demolition and installation.
Demolish the Cabinet-style Sink (Supplies needed: A bucket, wrench, utility knife and screwdriver.)
Turn off the water. Look for the two supply lines that feed hot and cold water to the faucet. Once the water is off, disconnect the supply lines.
Take out the p-trap. Connecting the sink to the wall, this trap still holds some water, even after you shut off the supply. Be sure to put a bucket underneath. You can unscrew newer fixtures by hand. Old fixtures may require the services of a wrench.
Cut through the caulk seals. A utility knife with a new blade is the best tool for the job. Cut through any caulking that connects the vanity top and sides to the wall. Remember also to cut the caulking between the vanity top and cabinet.
Look for mounting hardware. Some vanity tops are simply drop-ins. With the p-trap taken off, the supply lines out of the way and the caulk seal cut, lifting off the cabinet-style sink should be simple. If there is mounting hardware, go ahead and unscrew it.
Uninstall the cabinet. Use the screwdriver to uninstall all screws that hold the cabinet in place.
Prepare Wall and Floor
Note that you are now looking at a wall filled with holes, which may also sport a different paint job than the rest of the bathroom. The floor, too, may be different from what you are used to seeing. Be prepared to sand and paint the wall and possibly replace some flooring as well.
Position the Pedestal Sink
Unlike the cabinet-style sink, which rests on the cabinet, the pedestal sink actually mounts to the wall directly. Grab a stud finder and locate the two wall studs closest to the water hook-ups. Manufacturers usually specify a height of 30 inches; be sure that this works for you.
Tip: Read the documentation accompanying your sink; if you deviate too much from the recommendations, the pedestal portion may not fit.
Install the Sink Support
You need a hacksaw and screwdriver, as well as a 2x8-inch board. Open up the wall between the studs you have identified and install the wood as a support for the sink. Anchor it to the studs.
Tip: The smaller you keep the hole, the easier the patch job that will let you close it up. Do not overdo the cutting!
Brace the Sink
With the support installed and the hole in the wall fixed and painted over, it is now time to install the brackets that hold the sink portion of the pedestal sink in place. Use a level to ensure that the sink is straight; in fact, use two levels for good measure. Mark the area where you should drill into the sink support and temporarily mount the sink. Put a marble on one side of the sink. Is it level or does the marble fall off?
Warning: "It'll do" is not the type of philosophy you want to bring to this task. Mess up here, and you will regret it for years to come.
Get in the Pedestal
Uninstall the sink portion and turn your attention to the pedestal portion. Some pedestals must be bolted into the floor, while manufacturers of other brands simply advise you to caulk it around the floor. The water supply lines can usually be hidden inside the pedestal portion. If they cannot, you have the option of moving them -- if you are handy with the plumbing -- or dressing them up with brass fixtures to make them look very nice and fit in with your bathroom design.
Warning: Follow the manufacturer's recommendations. Failure to properly anchor the pedestal to the ground may void your warranty.
Verify the Final Fit
With the pedestal loosely in place, place the sink on top and verify that there is a good fit. If there is a gap, here is your final chance to fix it.
Install Sink and Pedestal
Following manufacturer recommendations with regard to height, screw type and bracket support specs, you are now ready to mount the sink. Attach the water supply lines and p-trap. Finally, get in the pedestal. Caulk around the wall. Turn on the water, and check for leaks.
Please note that these instructions work best in a "perfect world" setting, where the water lines are intact, connectors come off with a reasonable amount of force and there are no unwelcome surprises on the floor when you take out the old cabinet-style sink. In the real world, there is always the chance of busting a pipe, cutting through the pipe while making the hole between the studs or finding that years of slow leaks have rotted out your floor. Be forewarned that these situations may call for the help of a professional repair person.