Installing a Kitchen Sink

A shabby, discolored sink is an eyesore in a nice kitchen. If you're upgrading your countertops or you just don't want to look at your old sink anymore, it's time to put in a new one. Modern sink designs offer single, double and triple bowls; built-in drain boards; diverse sizes and styles; and more. Your plumber could put in a new sink, but it's a fairly simple matter to install it yourself; the job requires few tools and only modest skills. When you're done, you can admire your handiwork, congratulate yourself and then find a use for the money you've saved.

Selecting a Sink Sinks come in a pleasantly bewildering variety of styles, materials and colors. Many kitchen models have two or more bowls, along with three or more holes for mounting faucets and accessories like rinse hoses, instant hot water dispensers and dispensers for soap or filtered water. Stainless steel sinks are popular in contemporary kitchens, and traditional porcelain cast-iron sinks work nearly anywhere. Sinks made from new solid-surface materials come in a rainbow of colors and interesting finishes. For an easy swap-out, make sure the new sink is the same size as the old one; most are 33 by 22 inches. Obviously, you'll have to cut the counter to install a larger sink; not so obviously, that may not be possible if there's a dishwasher right next to the sink.

How many bowls? Most people prefer a double sink with two large bowls, one for washing and one for rinsing; a garbage disposal can go in either bowl. Others like a large main bowl and a smaller bowl where the disposal lives. Convenient for preparing food, this design also affords better control of what goes into the disposal. Triple-bowl sinks usually feature two large bowls with a smaller disposal bowl in the middle. This kind eats up about 4 feet of counter space, but it's a good choice for a busy kitchen, allowing (for instance) food preparation on one side and cleanup on the other. Still, cooks who frequently deal with big pots and big meals often prefer a large single-bowl sink.

What material? Enameled cast iron gives you a classic look. It's nearly bulletproof, it comes in an enormous variety of colors, and it looks elegant in a traditional or modern kitchen. There are disadvantages: The surface is prone to pot marks, chips and eventual wear. Cast iron is miserably hard to drill into to add an instant hot water unit or reverse-osmosis filter. And fragile items are likely to break if you drop them in the sink. A cast-iron sink is by far the heaviest choice, which means you'll trade increased huffing and puffing during installation (it will take two people to lift it) for a sink that's highly stable and solid.

Stainless steel is probably the most practical material, and many find it quite beautiful. It's lightweight, hygienic, virtually indestructible and easy to punch holes in for add-ons. It's also somewhat resilient, so dropped plates and glasses are less likely to break. The only disadvantage may be aesthetic: one person's "clean and elegant" is another person's "sterile." Stainless steel comes in many gauges, or thicknesses. We prefer at least 19 gauge for a sink. Higher numbers mean thinner metal and (usually) lower prices. A thin stainless steel sink, called builder's or contractor's grade, is often the least expensive choice. With thin stainless, though, just moving the faucet spout up and down may flex the sink, and cheaper sinks usually stain more easily.

Solid-surface sinks are made by quite a few manufacturers now, from mixtures that include resins, quartz, even granite. Advantages include original colors and textures, high stain resistance, moderate weight and good resilience. Color and texture run all the way through, so damaged spots can be sanded out. These sinks are no trouble to drill. Since solid-surface sinks are fairly new on the market, their ultimate service life is unknown, but it seems to be suitably long.

What mounting style? The four basic mounting types are self-rimming, rimless, under-mount and counter-over. Each style mates the sink to the countertop in a different way. Your choice of countertop material affects which mounting style you can use.

Self-rimming sinks have a lip that overhangs the countertop. They're easy to install and can usually be replaced without destroying the countertop. Self-rimming sinks work best with smooth countertop materials including plastic laminate, granite, marble and solid wood but they can also be used over tile. Self-rimming designs come in all materials. Since the rim overhangs the cutout in your counter, your cut doesn't have to be perfectly accurate. There is a downside, though. Because of the rim, you can't sweep water into the sink when you're wiping up the counter, and soil can build up between the countertop and rim, where it's hard to get at.

Rimless sinks use a separate mounting rim and clips that attach below the countertop to hold the sink in place. Rimless sinks work best with plastic laminate countertops. Like the self-rimming sink, the edges of this type can be difficult to keep clean. Under-mount sinks attach to the bottom surface of the countertop. They're often used with solid-surface counters. The cutout is sized so that the countertop will overhang the sink, and the edges are finished, so kitchen cleanup is easy. Under-mount sinks are generally not well suited for counters made with granite or other stone, however, because drilling holes for bolts that hold the mounting clips is likely to cause fractures. Counter-over sinks have a lip that fits under the countertop but on top of the counter's base material (typically plywood, particleboard or cement board). Because you attach the sink to a flat surface (the base for the counter), this type of sink works well when the countertop itself is made of an uneven material tile, for example. Where the tile goes over the sink's rim, mastic or silicone caulk can be used as an adhesive sealant. It's usually a tilesetter who installs the counter-over sink, after laying down the tile countertop. If the sink is lower than the countertop, the tilesetter closes the gap by running a course of quarter-round edge tile around the sink.

A variant, the "tile edge" sink, is attached on top of the countertop's base material, but it's elevated so that its edges are flush with the counter's finished surface, instead of below it. Its corners are squared off to relate to the countertop tiles, and a grout joint is run all the way around its edge. (This may be why this style is sometimes called a "mudded-in" sink.) Used in a stone slab countertop, this mounting method saves the expense of polishing the edges of the stone around the sink opening.

Many contractors install self-rimming stainless steel sinks as if they were counter-over models: they drill mounting holes in the rim, screw the sink down to the counter's base, and then lay in tile or a solid-surface material so that it overhangs the rim. This mounting style ensures easy kitchen cleanup.

Step by Step: Installing a Self-Rimming Sink Because the self-rimming sink is the most common type, we'll show you how to install one. Other types require only slightly different procedures, so you need only read the manufacturers' instructions and adapt the following sequence.

1. Mark the opening. Most sinks come with a template that helps you accurately mark the outline of the hole you'll need to cut in the countertop. If you don't have a template, take a few minutes to make one. Put a large piece of cardboard on the floor and set the sink on it upside down. (If your chosen sink is a heavy one, get some help lifting it for this and subsequent steps.) Use a felt-tipped pen to trace the sink's outline onto the cardboard. Remove the sink; then measure and draw another line 3/4 inch inside the one you just drew, all the way around. Cut along both lines to create the template for your sink. The inner edge of the template shows you the edge of the hole that will be cut in the countertop; the outer edge lets you see where the edge of the rim will be, so you can check clearance to the counter edge and wall.

Now use the template to pick a location for the sink. When you're sure it's exactly where you want it, stick the template in place with a couple of pieces of masking tape, then use your felt-tipped pen to draw a line around its inner edge, directly onto the counter. If the counter's color is too dark for the line to show up, put down masking tape first and trace your line onto the tape.

2. Cut the opening.
Note: You won't be cutting your own countertop if your choice of surface is granite. Fairly sturdy once in place, it is otherwise fragile and difficult to cut. The company that supplies your countertop will cut the hole for the sink, using your specifications. But you'll still need to cut a hole in the subsurface.

Drill a hole (3/4-inch or larger) at each corner of the marked opening. If you use 1- or 2-inch-diameter hole saw, your cuts will serve as rounded corners, which will make for a stronger installation. Now use a jigsaw to cut along the marked lines, stopping just short of the corner holes. If you're cutting through laminate or another finish surface, put duct tape or masking tape on the saw shoe the plate on the saw's base that the blade sticks through so it won't scratch your countertop. If you're cutting a molded countertop that includes a backsplash, there may not be adequate clearance for the jigsaw, so use a handsaw or reciprocating saw to cut along the back line. From underneath, drive shims into the saw kerfs in a few spots (shingles are perfect for this). This will keep the cutout from dropping suddenly as you complete the cuts at the corner holes. Lift out the cutout piece, using the corner holes for finger holds, and then use a rasp to remove splinters and excessive roughness from the opening. If you are installing a cast-iron sink that has corner gussets, you may have to round the edge of the cutout slightly.

3. Install the sink. Put your fingers through the sink's drain and fixture holes, and carefully lift it and place it in its hole. (You'll probably want to wear gloves to keep thin-edged stainless sinks from cutting you and prevent heavier ones from pinching.) If you're worried about scratching the countertop, lay scrap sticks along the sides of the opening, put the sink in place, and then remove the sticks one at a time.

After checking the fit of the sink in the opening, lift it out again and finish any trimming that's necessary. This is a good time to attach the drain basket, faucet assembly and accessories; these are a lot tougher to mount once the sink is in place. (You may want to check out our article on the basic modern toolkit.) If gaskets weren't provided, be sure to pack the undersides of these fixtures with plumber's putty (not silicone caulk) before mounting them.

To create a cushioning gasket for an iron sink, lay a bead of silicone caulk all the way around the opening so that the edge of the sink's rim will bear down on it. Silicone caulk creates an effective water seal and acts as an adhesive so the sink won't move. Once the sink is in place, run another bead of caulk around its edge. This is especially important if your countertop is tile because the silicone will keep water from seeping in between the countertop and the sink.

Center the sink and remove excess silicone with your moistened finger. Then (and this is specific to a self-rimming stainless steel sink) use a long screwdriver to fasten the retaining clips that secure the sink to the underside of the countertop. At the back, where space is tight, you may need a particularly long screwdriver. You may want to glue or screw scrapwood bracing strips to the underside of the countertop so that they contact the bowl on at least two sides. This will ensure that the sink doesn't move.

Connect the faucet and drain, and you're good to go. One final caveat: Don't use harsh abrasives to clean your new sink. That way, it'll look new for many years to come.