How to Install a Kitchen Sink

Replacing a kitchen sink is straightforward unless you are buying a larger sized sink that will require resizing the cutout in the counter tops. In such cases you will need to hire a profession to cut out the new opening particularly if you have granite counter tops. However, in cases where the dimensions will remain the same, installing a new sink is not that difficult of a job for the average homeowner, even though unfamiliar with working with plumbing. After all, there will only be a couple of flexible plumbing pipes to screw in because you are not rearranging the existing plumbing. At most you will have to disconnect, the reconnect the drain and hook up the hot and cold water to appropriate spigot.

To minimize the work, measure your old sink before you remove it and use that measurement when searching for a new. If you are planning on installing a new rimless sink, remember that those are installed n cutouts larger than their actual dimensions to allow for more space for the undermount.

For self-rimming sinks, the original cutout is normally fine provided your measurements are correct.  The cutout is typically smaller than the actual sink because the lip rests on the counter.

Before You Begin

If you have decided that you are definitely going to replace a sink, you will need the following tools and materials.

  • New sink of your choice
  • Plumber’s putty and silicon caulk
  • 1 ¼ finish nails
  • 5 minute epoxy
  • Acetone
  • Teflon tape
  • Adjustable wrench
  • Phillip and flathead screwdriver
  • Putty knife
  • Hand saw
  • Caulking gun

You might want to remove the old sink first before you buy the new one, and measure the cutout without any sink inside it. This is important if you are changing from one type of sink mount to another, such as going from a self-rimming to a rimless version.

If you are widening an opening such as a laminate countertop, you will need kraft paper to draw out a template and 150-grit sandpaper to smooth out the rough edges. If the opening is too wide for your sink, you will also need strips of wood to narrow the gap.

Removing the Old Sink

The first steps of the project involve disconnect the drain and hot and cold water lines from theHow to Install a Kitchen SinkCredit: Opensource old sink.  This will require that you go under the cabinet of course. For this discussion, it will assume you are removing a self-rimming sink.

Note: If you have a garbage disposal, turn off the power to the unit at the breaker box, then loosen the locking ring and place the unit out of the way for the time being.

  1. Turn off the water shutoff valves under the sink for both hot and cold. Open the faucet above to let any remaining water in the system flow out and drain.
  2. Loosen the coupling nuts for the waste line and remove the trap slowly because it will still contain drain water. Dump the water out in a bucket.
  3. Undo the connecting nut attaching each water line supply to its shutoff valve.
  4. Now there is nothing holding the sink in place except the clips underneath and maybe some silicone caulk. Look under the cabinet and unscrew the clips around the perimeter.
  5. Up above the cabinet, use a putty knife to pry under the edge of the sink.
  6. The sink should now be free to lift out of the opening.
  7. If you are going to be transferring the faucet to the new sink, remove it at this time.

Preparing the Opening

If the opening is too large to support the new self-rimming sink, you must build out all sides of the inner area with small pieces of wood. Attach the strips using a 5 minute epoxy then nail securely with finishing nails into the side of the counter.

If the opening is too small for the new sink, you will need to make a paper template for a larger opening. Most manufacturers provide a template to use for cutting the opening. If not, you can use kraft paper.

To use the template, cut around the outline with scissors the tape the template in place on the countertop. Now trace around the perimeter of the opening with a pencil, then remove it and make the cut with a hand saw. Now smooth the edges with 150-grit sandpaper or a sand block.

Clean the countertop edges with acetone to remove any residue. After the area has dried, apply a bead of silicone caulk or plumber’s putty around the perimeter of the countertop where the lip will rest.

Installing the Faucet

If you are going to use your old faucet, put a plumber’s putty around its base. If you are installing a new faucet, use the gasket that is provided. Now place the faucet and any sprayers or soap dispensers in place and tighten the mounting nuts on top. Turn the sink over and tighten the coupling nuts for each faucet component with an adjustable wrench.

Installing the Drain

At this point in replacing the sink, you should replace the drain, otherwise known as the strainer, at the bottom of the sink.  With any new one, it should include a gasket to go between the new drain  and sink. If not, you can apply a bead of silicone caulk or plumber’s putty.

To install the strainer, turn the sink on its side and have someone hold the strainer in place in the sink while you tighten the locknut.

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Install the Sink

Place the sink into the hole. If the sink is heavy, you can use strips of wood on the edges to wedge it lower without pinching your fingers. If any caulk squeezes out, wipe it up with a cloth. Finally, go under the sink in the cabinet and tighten any clips to hold the sink firmly in place.

While the sink, inspect the supply lines for damage. If worn, replace with flexible tubing. Wrap Teflon tape around the thread of both water supply lines and attach both to their respective shutoff valves with an adjustable wrench.

Finally, attach the tail piece coming from the drain to the waste line to complete the plumbing connections. Turn on the shutoff valves to restore water to the faucet. While the faucet is running, check for leaks under the cabinet. Watch the area over the next couple of days to see if you see any watermarks from leaks.

Final Thoughts

How to Install a Kitchen Sink
Credit: Opensource

Installing a new sink is not a difficult job for the average DIYer. You will have to disconnect the trap underneath the sink temporarily but that is the extent of the plumbing issues you will deal with. If you do not have to make any adjustments to the opening in the countertop, then the process will go much faster because you are essentially just dropping the sink in as is.

However, while you have everything open and disconnected, I recommend that you change the faucet, strainer and both water supply lines with newer options. The entire process as described above should take about two to three hours depending on your experience.