Replace a Kitchen Sink and/or Fixture

Like the rest of your house, kitchen sinks and fixtures—spigots and faucets—have this way of wearing out. (If they haven't worn out, they are no doubt reminding you of the former owners' stale taste.) Sink and fixtures are usually easy to replace, although it does entail some overhead work. If you are replacing the sink and the fixtures, make most of the connections before mounting the sink. That will save wear and tear on your back—and your disposition.

Modern plumbing fixtures are surprisingly easy to work with, although you'll have to find the right connectors to mate them to the pipes under your sink. Look for knowledgeable folks at the store, and recognize that return trips to the store come with the territory of plumbing.

Sink projects can take several forms:

• In the following, we will install a sink and fixture in a partly finished tile countertop. Please make sure you understand how to replace the countertop before beginning.

• If you are replacing only the spigot and faucets, see “If You Are Replacing Just the Fixtures,” later.

• If you're replacing a sink with an identical size and mounting style, skip the section on sizing the cutout.

Seeking Sink Styles

Kitchen sinks are sold with three or four holes for fixtures. Depending on design, the faucets and spigots use one to three holes. You can put a sprayer, a soap or lotion dispenser, an air break for the dishwasher, or a filtered-water tap in the other holes. We bought a four-holer and capped one with a plastic cap; maybe later we'll put a water filter outlet in the hole.

Most fixtures fit a standard hole pattern, with holes 4" apart. If your fixtures fit a nonstandard pattern, see Install a Pedestal Sink for details on connecting them.

Sinks come in several mounting varieties:

• “Self-rimming” sinks, made of plastic composite, cast iron, or stainless steel, have a rim that sits on top of the counter. They are easiest to install, but the rim always seems to need cleaning. Stainless sinks are light, so they need clips to hold them in place. Plastic composite and cast-iron sinks can be held in place with caulking.

• Tile-in sinks rest flush with the tile, or slightly below it.

• Undermount sinks rest below the counter. They are difficult to mount because you must cover the exposed edge of the counter.

If you're replacing only the faucets and spigot, but not the sink, plan on spending some time upside down inside the sink cabinet. A basin wrench and flashlight on a stand will both come in handy. The basic sink connections are the same, however; the following explains the necessary steps for faucet replacement:

1. Close the stop valves and loosen the fixture mounting nuts with a basin wrench or an open-end wrench. (Some faucet assemblies are mounted with a single nut; others use one or more locking rings.)

2. Remove the water-supply tubes at both ends. It's best to replace the tubes, but if they are in good shape and flexible, they may be reused. Note that water-supply tubes often have different sizes at each end: ³⁄₈" × ¹⁄₂" is a common size.

3. Clean the sinktop. Use steel wool for stainless and nonabrasive cleaner for others.

4. If, after attaching the water supplies, they will fit through the appropriate hole in the sinktop, attach the supplies now.

5. If the new faucet mounts through a single hole and the water supply tubes will not fit through the hole after they are attached, mount the faucet to the sink first, and then attach the top ends of the water supplies from inside.

Step 1: Locate the Cutout

In this section, we'll assume you're installing a self-rimming sink in a countertop that you can cut with a jigsaw. Some counters can be cut only by installers or manufacturers. If that's your situation, go to Step 2: Mount the Fixtures First.

If the sink comes with a cutout template, use it. Otherwise, mark the cutout as follows:

1. Stick wide masking tape on the counter, on the approximate sink location.

2. Place the sink upside down on the tape, centered on the opening, with at least 1¹⁄₂" clearance to the back splash, and parallel to the front of the counter. (Note: This method will fail with an asymmetrical sink. Measure the opening and mark the cutout instead of tracing it.)

3. Mark on the tape around the perimeter of the sink.

4. Remove the sink and measure the amount of overlap. Measure the amount of overlap on the sink and subtract ¹⁄₈".

5. Drill through the countertop at the corners; then make the cutout with a jigsaw.

Step 2: Mount the Fixtures First

If you are installing a sink and faucet, do everything you can before mounting the sink. And read the instructions: Faucets vary widely in the way they are mounted and connected. Occasionally, manuals can be helpful.

Attach the Faucets and Spigots

Attach the faucets, spigots, or the one-piece unit to the sink. The attachment may be made with a single ¹⁄₂" nut or a large lock ring, as shown. When attaching a metal ring to a metal pipe, plumber's grease will prevent rust.

Attach the water supply tubes. Tighten the supply tube with a wrench.

Attach the Dishwasher Air Gap

A dishwasher air gap is a safety measure. If the drain plugs, the dishwasher will dump its wastewater into the sink, not into the sink cabinet. As a fringe benefit, it puts a slug of hot, soapy water into the drain, helping keep it clear.

Attach ⁵⁄₈" and ⁷⁄₈" tubing to the air gap with hose clamps. Leave the hoses long enough to connect as shown in the diagram. Then attach the air gap to the hole in the sink. The air gap prevents floods if the dishwasher drain plugs.

Step 3: Connect the Tailpiece and Drain

The top of the sink is now connected. The type of drain connections depend on whether you will be installing, or reinstalling, a garbage disposal.

Disposal Duties

Disposals require a specific type of tailpiece connection, which attaches with three screws. If you have an existing disposal, it's simplest to use the existing attachment if it is in good condition. To replace the disposal, shut off the circuit, disconnect the wire, remove the disposal, and install the new one, following directions that come with it. To install a disposal on a new sink, attach the tailpiece, and then follow directions for the disposal.

Connect the Tailpiece

If you're not installing a garbage disposal, connect a tailpiece to the new sink with silicone caulk. Masking tape will protect the sink and tailpiece from the caulk, which can be tough to remove. Trim masking tape away from the flange on the tailpiece.

Place silicone caulk on the bottom of the upper tailpiece and push it through the sink drain hole. Assemble the rubber washers and the housing, and then tighten the lock nut and wipe off extra caulk. When the caulk is dry, remove the masking tape.

Step 4: Mount the Sink

Now that you've made the cutout and connected the faucet, water supplies, and drain, turn your attention to mounting the sink. Various mounting styles for sinks are described earlier in the chapter.

The sink shown mounts in a tile countertop; you can do the tiling either before or after mounting the sink. If you tile first, you'll have to make a precise place for the sink. If you place the sink first, the faucet may get in the way of tiling. We brought the tile near the sink, placed and connected the sink, then finished tiling.

Finally, it's time to place and fasten the sink. Stainless-steel sinks are lightweight and should be held down to the counter with concealed clips.

For plastic and cast-iron sinks, put the sink in its final position. Mask the countertop with tape, right next to the sink. Remove the sink and place silicone caulking on the countertop, then reposition the sink. Stopper the drain, fill the sink with water to weight it down, clean off extra caulk around the edges, and let the caulk set overnight.

Step 5: Connect the Drain and Dishwasher

At this point, you've made most of the connections in a comfortable position. It's time to dive under the sink.

Connect the Drain

Kitchen sinks use a 1 ¹⁄₂" P-trap, which can be adjusted in angle and length. The trap connects with slip nuts and big washers. If the drain parts do not reach, buy an extension tube.

As you tighten the slip nut with pliers, make sure the big washer seats smoothly.

Connect the Dishwasher

The dishwasher air gap is already connected, but you need to connect the lower end of the tubes. Connect the ⁷⁄₈" tube from the air gap to the Tee connector. Wastewater from the dishwasher exits the air gap and enters the Tee connector, just below the tailpiece.

Connect the ⁵⁄₈" tube from the air gap to the dishwasher outlet.

Step 6: Connect the Water Supplies

With the sink in place, and the drain and dishwasher connected, make the final connections to the water supply tubes.

Remove the spigot strainer so it does not catch rust or sediment from the pipes. Open the stop valves and check the faucet operation. Replace the strainer.

Feel the plumbing underneath, and if your hands stay dry, you're done! If not, check and gently tighten connections. Major leaks indicate that a washer is missing or badly placed.

Excerpted from The Complete Idiot's Guide to Simple Home Improvements © 2004 by David J. Tenenbaum. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.

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