Different types of sinks have slightly different installation directions. For instance, surface-mounted sinks generally need caulking and clamps; however, self-rimming porcelain sinks need only caulk. And, you also have to consider what material you’re installing the sink in. But, regardless of what material you’ve chosen for your counter or sink, there are eight general rules that apply to installing any sink that you can follow below.
Step 1 – Trace the Template Onto the Countertop
Most sinks come with templates in the box. Carefully position the template on the newly laminated countertop or the plywood base.
Try to center the template, but leave at least 1 1/2 inches, and not more than 3 inches, from the edge of the counter. Draw a pencil line around the edge of the template. Your template should be for the proper size of the hole, not the overall size of the sink and flange. If it’s not, measure inward 1/2 inch and draw another line inside of that sink line.
Step 2 – Cut out the Sink Hole
“Double check all your dimensions before cutting the countertop. If installing a stainless-steel sink, make sure you have enough room for the clamps under the counter,” our plumbing consultant Wayne McCarthy says.
Drill a hole large enough for a jigsaw blade to the inside of each corner of the inside line. Cut along the inside pencil line with your jigsaw, while another person supports it from below. Then, lift that waste piece out.
Step 3 – Install the Faucets
Individual faucets will have different manufacturer's instructions to follow. Some are mounted through the holes in the sink using plumber's putty, while others require separate holes to be drilled through the countertop. Either way, it is easier to put the faucet and strainer on before the sink is installed. Use an adjustable wrench to tighten up the hardware that holds the faucet in place.
Step 4 – Install the Supply Lines
Supply-line connector kits are available that contain the flexible chrome pipe, hardware, shut-off valves, and instructions. It’s up to you what the diameter and material of your supply pipe will be, depending on your sink type and whether you will be adding a dishwasher. If you want a dishwasher, you will need to install a special T-shaped shut-off valve.
Step 5 – Install the Basket Strainer
Pack the basket strainer with plumber's putty, and push it firmly down into place. Where the strainer is threaded underneath, slip on the washer and then tighten down the lock nut until the putty oozes out. Clean off all excess putty.
Step 6 – Caulk and Install the Sink
For porcelain, cast-iron, and enameled-steel self-rimming sinks, place a bead of latex caulk along the entire bottom edge of the upside-down sink. Choose a caulking that matches the color of your countertop. Position it carefully over the opening and press it down until excess caulk oozes out along the edges. Follow the manufacturer's instructions for installing any additional hardware that comes with or the sink.
For stainless-steel sinks, use plumber's putty instead of caulking. Put the putty under the lip or flange of the sink. Let any excess ooze out, and remove it with a putty knife after the clamps are tightened.
When using latex caulking on other types of sinks, have a container of clean water and a clean sponge or rag available for wiping the caulk around the edge of the sink.
“After the sink is set and caulked, place two 1-gallon containers of water in the sink to hold it down until the caulking dries. Allow at least 4-5 hours for the caulking to cure before hooking up the water and drain,” McCarthy suggests.
Step 7 – Install the P-Trap
Next, install the P-trap by connecting the tail piece to the basket strainer. Use a slip nut over the washer. Then, connect the P-trap to the tail piece with another washer and slip nut. Attach the P-trap to the wall stub-out with a curved drain-extension pipe.
For two-bowl sinks, you will need an to use an end outlet waste pipe to connect the two bowls into one drain.
Step 8 – Check the Sink
After you’ve hooked the drains up, fill the sink and check for leaks around the strainer.
Wayne McCarthy, a professional plumber, contributed to this article.