Installing a Kitchen Sink

Intro

Once you have the proper hole cut in the countertop, it's time to install the sink. You could put in the sink and then attach the faucet, garbage disposer, and drain from below. But it's much easier to attach those elements to the sink first, then put the whole assembly in place.

Spread a drop cloth on the countertop and set the sink upside down, with the faucet holes overhanging the edge. Or set the sink on two sawhorses, padded with rags or towels.

Enameled-steel and stainless-steel sinks clamp to the countertop with special clips that are usually included with the sink. Test to make sure that the clips will work on your countertop before you install the plumbing. A cast-iron sink is heavy enough to stay in place without clips.

Prestart Checklist

Time
About half a day to install a sink with disposer and dishwasher connections

Tools
Drill, screwdriver, groove-joint pliers, adjustable wrench, strainer wrench or spud wrench

Skills
Connecting a trap, installing a faucet and garbage disposer

Prep
Install the rough plumbing, a switched receptacle, and the cabinets

Materials
Sink, faucet, garbage disposer, appliance extension cord, wire nuts, trap assembly, supply tubes, flexible copper line for dishwasher and icemaker supplies, drain hose (usually included with the dishwasher), air gap, plumber's putty, drop cloth

Previous | Next

Choosing a Sink

When it comes to the quality of sink materials, you get what you pay for. An inexpensive stainless-steel sink flexes when you push on it, scratches easily, and is difficult to keep clean. A higher-quality, heavier-gauge (6- or 8-gauge) stainless-steel sink, such as one with a burnished finish, is a better choice. If you opt for a stainless-steel sink, make sure the underside is well coated with sound-deadening insulation.

Enameled cast-iron sinks come in a variety of colors; they last much longer than enameled steel sinks. Acrylic sinks have the look of enameled cast iron, and the higher-end models are nearly as durable. Both cast-iron and acrylic sinks have insulating properties, so water stays warm longer than it does in a stainless-steel sink.

Step 1

Install a standard basket strainer in one sink hole and the garbage disposer strainer in the other hole. Make sure you know which strainer goes to which hole. Place a rope of putty under the lip of the strainer body and hold it in place as you slip on the washers and tighten the nut.

Previous | Next

Step 2

Following the manufacturer's instructions, prepare the garbage disposer mounting hardware for installation. Open the electrical cover plate and hook up an appliance extension cord using wire nuts. Replace the cover plate.

Previous | Next

Step 3

Slide the garbage disposer mounting ring over the flange. Then install the cushion mount, making sure the groove on the inside fits over the lip of the sink flange. Position the disposer over the flange; push down and twist until the disposer is fully anchored.

Previous | Next

Underhung and flush-mounted illustration

Other sink installations

A flush-mounted or underhung sink makes for easier cleaning, but these styles require special countertop treatments.

Install a flush-mounted sink with its rim resting on plywood substrate. Install cement backerboard on the top up to the edge of the sink, and cover it with tiles that partially overhang the sink flange.

Install and plumb an underhung sink after the substrate is installed. Then install tiles as shown, with cut pieces along the perimeter and bullnose trim pieces overlapping them.

Step 4

Assemble the drain pipe. Begin by installing the tailpiece and the arm that attaches to the disposer. Cut pieces to size as needed, then install the trap. Set the sink in the hole to see whether the trap lines up with the trap adapter in the wall; you may need to trim a piece or add an extension.

Previous | Next

Step 5

Attach the air gap with a mounting nut. Run a 5/8-inch hose from the air gap to the disposer. Secure the hose with hose clamps. If the drain hose is easily disconnected from the dishwasher, attach it to the air gap now. Otherwise, attach it when you install the dishwasher.

Previous | Next

Step 6

Install the faucet. If the faucet does not come with a plastic or rubber gasket, place a rope of putty under the faucet's flange to seal out water. Tighten the mounting hardware.

Previous | Next

Step 7

Screw flexible supply tubes onto the faucet inlets. Make sure that the tubes are long enough to reach the stop valves, and that their ends are the right size to screw onto the valves. If the faucet has flexible copper inlets, use two adjustable wrenches to avoid kinking the inlets.

Previous | Next

Step 8

To make your work easier, hook up as much plumbing as possible before you set the sink in the hole. For instance, now is a good time to attach the supply lines for the dishwasher and icemaker.

Previous | Next

Step 9

Place a rope of plumber's putty, thick enough to seal at all points, around the bottom lip of the sink. Position at least some of the mounting clips in the channels and hold them upright, using dabs of putty. Turn the sink right side up and carefully lower it into the hole.

Previous | Next

Step 10

From underneath, turn the clips so they grab the underside of the countertop. There should be a clip every 8 inches or so. Tighten each clip with a screwdriver or a drill equipped with a screwdriver bit.

Previous | Next

Step 11

Attach the trap to the trap adapter in the wall. Tighten all the connections with groove-joint pliers. To test, fill each bowl with water, then remove the stopper and watch for drips. Run the disposer with the water on and check for drips.

Previous | Next