How to Install a Bathroom Countertop Sink

Beth Asaff
Newly Installed Bathroom Sink

Renovating the bathroom offers instant gratification and a installing a new sink is a great way to start your bathroom redo project. Bathrooms are just one of those primary rooms in a home that have the ability to look and feel so completely shiny and new when revamped. Even something as simple as changing out a drop-in sink for a new version can have a huge impact on the bathroom's design.

Counters and Self-Rimming Sinks

Self-rimming sinks are most commonly used on laminate counters, which require their interior edges to be hidden by the rim of the sink. It is possible, however, to install a decorative self-rimming sink on other types of counters as well, including:

  • Granite and Quartz: Supply the fabricator with the template of the sink so they can cut the correct sized hole
  • Tile: The smoother and more level the tiles, the easier the install will be. Avoid handmade tiles on the counter to help the sink sit flush. You will need to cut out the sink's hole first, and then tile the counter, avoiding the sink cutout.

Cutting a Hole for the Sink

If you are using a laminate counter or are planning on tiling a counter, you will need to cut a hole for the sink first. However, if you are installing a drop-in sink of the same size and shape as the one previously there, no cutting is necessary and you can skip to the installation instructions.

What You Need

  • Sink template
  • Drill with 3/8-inch bit
  • Saber saw

What To Do

Installing a sink
  1. Turn off the water valve.
  2. Use the sink manufacturer's template to draw the cutout line on the laminate countertop or plywood. If a template is not included, set the sink upside down on the countertop, trace the outline, then draw another line about 3/4- inch inside your first line, which will become your cut line.
  3. Carefully drill a 3/8-inch starter hole inside the first cut line.
  4. Cut along this line with a saber saw. Insert the end of the saw into the starter hole to help it get going. Remove the piece at the end.

How to Install a Self-Rimming Countertop Sink

This particular bathroom sink install is relatively easy for anyone to take on, and enhances the look of any bathroom.

What You Need

  • Self-rimming, drop-in sink
  • Wrench
  • Silicone caulk

How to Do It

  1. If you haven't already, turn off the water valve.
  2. Install the drain on the sink. Squeeze a thin bead of silicone caulk around the drain and push the tailpiece of the drain into place. Set the collar in place and tighten the bolt from below with the wrench to hold it down.
  3. Squeeze a thin bead of silicone caulk around the perimeter of the sink cutout on the counter.
  4. Lower the sink into place on the counter.
  5. Squeeze a second bead of caulk around the outside perimeter of the sink's rim to seal the sink in place and make it watertight. Run your finger over the bead of caulk to smooth it into place.
  6. Install the faucet, hook up the waste pipe to the tailpiece and turn on the water.

Tips and Troubleshooting

Installing a sink
  • Cast iron sink installation will require the use of a bead of plumber's putty rather than adhesive, to seal the edges
  • Look for little wedge-shaped seals that have a habit of sticking to the drainpipe. They enable the plastic nut to stick onto the stem of the sink. Carefully check out this configuration and be sure to duplicate the configuration on the new drainpipe.
  • Test the fit of the sink on the counter before adding the caulk.
  • Install the sink and faucet on a loose counter whenever possible, then install the counter on the cabinet.

Enjoy Your New Bathroom Sink

This project can be completed in an afternoon. Whether you are swapping out a sink of the same shape and size for a new one, or changing the counter as well, a new sink can dramatically improve the look of a bathroom. Give your bathroom a mini facelift with a new sink today and see where the transformation takes you.

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How to Install a Bathroom Countertop Sink