How to Replace a Cracked Granite Top Sink

Turn off the water supply to the sink using the shutoff valve attached to the pipes beneath the countertop. Turn on the faucet to run the remaining water from the pipes. If the sink has already begun leaking, place a bucket beneath the faucet to catch the water.

Disconnect the water supply from the sink faucets using an adjustable wrench to remove the compression nuts at the end of the sink faucet supply hoses from the house pipes. Pull the supply hoses free.

Remove the sink trap at the base of the sink that connects the drainpipe beneath the sink to the house drainpipe. Use a pipe wrench to twist off the large slip nut holding the U-shaped sink trap connected to the straight tailpiece pipe descending from the sink drain. Pull the slip nut away from the sink trap and disconnect the pipes at the joint. Use a pipe wrench to remove the end of the tailpiece pipe connected to the drains of the sink by unscrewing the large nut at the base of the drains. Pull the tailpiece pipe free and set aside.

Remove the retaining nuts beneath the faucet, using a socket wrench and holding the faucet in place. Pull the faucet from the hole in the countertop and set it aside.

Examine the sink to determine how it’s secured into place. An undermount sink that’s placed beneath the hole in the countertop is held to the countertop using clips on either side of the sink. Sinks mounted to the top of the counter are typically held in place by the weight of the sink upon the small lip surrounding the sink and overlapping the sink hole edge. The type of mount determines the method of removal.

Remove undermount sink by unscrewing the clips holding the sink in place. Place a support beneath the bowl of the sink before removing the screws holding the clips in place with a Phillips screwdriver. A concrete block can provide a stable strong support. After removing the clips, run a putty knife through the joint between the sink and countertop to break the seal of the caulk used as an adhesive for additional support. Lower the sink from its mounted position.

Remove top-mounted sinks by running the putty knife between the lip of the sink and the countertop to break the adhesive seal of caulk. Pull the sink up and out of the mounting hole.

Replace the sink with a model of the same size. Lay a bead of caulk around the lip of top-mounted sinks before setting them into the mounting hole. Use a bead of epoxy adhesive along the top rim of an undermounted sinks before placing it against the bottom of the countertop hole with the sink opening aligned with the hole opening. Replace the clips alongside the new undermounted sink to hold it in place.

Replace the faucets into the faucet hole on the countertop, sealing the base to the countertop by placing a bead of caulk along the edge. Restore the pipe connections by reversing the removal process.

Place a bead of caulk around the edge of a top-mounted sink and around the edge of the faucet plates held against the countertop to prevent water leakage into the cabinetry below. Turn on the water supply and then test all pipe connections for leaks by running water through the sink. Make adjustments where needed by turning off the water and reconnecting leaky pipe joints properly. Once any leakage is stopped, you can use the newly placed sink normally.