Enlarging Cutouts in Tile Countertops

Shut off the water to the sink. Unhook the water supply from the faucet and the waste pipe from the sink using the wrench.

Slide a utility knife around the perimeter of the sink to cut the adhesive holding it in place. Lift the sink off of the tile counter.

Cut the grout out from between the tiles surrounding the sink opening. You need to remove the tiles from the area you want to enlarge. If this area extends over half a tile, the entire tile needs to be removed and a new, cut tile installed. Dig out all the grout from around these tiles using a utility knife.

Examine the edge of the tiles where they abut the sink opening. Slide the edge of the putty knife beneath the edge of the tiles and hit the handle with a hammer to slide the putty knife beneath the tiles. This can cause the tiles to pop up off of the counter. Remove all the tiles from the area you want to enlarge.

Place the new sink upside down on the counter and trace its outline with a pencil. Measure in 1/2 inch from this pencil mark and draw a second outline. This is the line you cut on to enlarge the opening.

Make the sink opening larger by cutting along the inner outline with a jig saw. Cut through the counter beginning in the existing cutout, moving out to the outline and around.

Place new tiles around the perimeter of the new sink cutout to check their fit. Mark them to be cut with a pencil and cut them to fit around the opening on a tile wet saw.

Apply a thin coat of thinset mortar directly onto the backs of each tile with a trowel and press them into place on the counter around the cutout's perimeter. Allow the mortar to cure for 24 hours.

Grout the new tiles into place by spreading the grout over them and the adjoining tiles with a grout float. Scrape the float over the tiles at a 45-degree angle to push the grout between them, then turn it to 90 degrees to remove the excess grout.

Allow the grout to set up for 10 minutes, then wipe the tiles clean with a damp grout sponge. Let the grout cure for 24 hours.

Squeeze a thin line of silicone caulk adhesive around the perimeter of the sink cutout and lower the new sink into place. Hook up the sink and faucet and turn the water back on to test the new sink.