Tiled countertops are used in many parts of the country as a practical way to create a waterproof surface for the vanity. Over time, however, tiles can crack and grout can become discolored. When this happens, the entire vanity can begin to look dated. Replace your old tiled vanity top with a marble top to update the vanity and give the entire bathroom a facelift at the same time.
Have Measurements and a Template
Marble vanity tops are available in a range of standard sizes, but they can also be made to order. Take careful measurements of your existing vanity top before purchasing or ordering your new marble top. Tiled tops do not have to be standard, which may mean you need to order a marble top cut to fit your existing vanity. If this is the case, create a template for the marble to be cut from. Place a large piece of cardboard over the existing top and cut it to those dimensions. Mark the position of the sink and any faucet devices for an accurate cut.
Remove the Existing Top
Tiled countertops are usually built onto a piece of plywood or cement backerboard that has been caulked and screwed to the vanity. Turn off the water to the sink and disconnect any plumbing extending to the sink and the faucet. Examine the underside of the top for screws and remove any you find. If there is no caulk, the top will lift off now. If there is caulk, run a utility knife around the underside of the existing top to cut it free. You may also have to run the knife around the perimeter of where the top meets the wall if it has been caulked there as well. Lift the top, sink and faucet away at once.
Install the Sink and Faucet
Your new marble top may come with a sink bowl already attached, or it may need to be installed on site. Install the sink and the faucet before you install the marble top on the vanity. Test fit the top on the vanity first to ensure it does fit, then flip it upside down on a nearby table. Squeeze adhesive around the perimeter of the sink cutout and press the sink upside down around the cutout. Push the stems of the faucet valves and spout up from the top of the vanity and tighten the washers and nuts from the underside to secure them in place.
Install the Vanity Top
Squeeze a thin bead of silicone caulk adhesive around the perimeter of the top of the vanity. Slowly lower the vanity top down into position, then lift it up again after it makes contact with the adhesive. This will cause the adhesive to string upwards slightly, exposing it to air and strengthening the bond it will make between the marble and the vanity. Lower the marble back into place. Install the faucet handles, and hook up the plumbing under the sink, installing the water and faucet lines and P-trap. Turn on the water and test the faucet and sink.