How to Change From a Single-Bowl to Double-Bowl Kitchen Sink

Turn off the water to the sink by twisting the shut-off valves clockwise under the sink. Turn on the faucets to make sure there is no residual water left.

Place a bath towel under the sink to catch the small amount of water from the pipes and sink when you remove them. Have a bucket ready for the drainpipes.

Disconnect the flexible water lines that lead to the cold water and hot water faucets. Use an adjustable wrench if the connections are too tight to unscrew by hand.

Unscrew the P trap under the sink with the wrench, loosening it until you can lift it away from the other drainpipes. Empty the trap into the bucket. Twist the drainpipe back so it will be out of the way until you are ready to install the new sink.

Look under the sink for any clips holding the sink to the countertop and release them. Slide a putty knife under the edge of the sink around the countertop to break away any putty or caulk holding the sink down.

Lift the sink from the countertop. Use depth and width measurements of the old sink to purchase a new sink. Sink sizes are based on the countertop opening, not the number of bowls.

Attach any faucets, hoses and drains to the new sink before you install the sink. Attach each component according to the manufacturer’s instructions.

Caulk around the perimeter of the countertop opening with a thick bead of waterproof kitchen caulking.

Set the sink into the opening, pressing it firmly into the bead of caulk. Wipe up any residual caulk with a damp rag. Attach any clips under the sink to hold it securely to the countertop.

Bring the two drains together with a Y-pipe. Connect the P-trap and screw the pipes securely together. Attach the dishwasher drain and then the flexible water lines. Turn the water valves on and let the water run for a few seconds to clean the lines.