How to Install an Undermount Sink

Undermount sink installation can be a challenge, especially if you do not have any experience with plumbing. An undermount sink gives a clean, simple look to both bathroom and kitchens.

The difference in the design of an undermount sink is that there is no edge or lip surrounding the top of the sink, which means you can easily wipe debris from the countertop into the sink directly. You should only use them with solid countertops to protect from water damage.

Undermount Sink Installation

  1. Choose the right style and size undermount sink for your space. A single, double or specially designed bowl is available for just about any home application. When selecting the right sink, be sure to consider the countertop's design and have the appropriate hole cut into the countertop to match the sink's shape.

  2. Cut the necessary holes by following the template provided to your by the sink's manufacturer. After tracing the sink and faucet hole placement onto the countertop, cut the holes out using a 3/8 inch drill to start the hole and then finish it with a saber saw. Also, drill out the holes for the mounting screws according to the template provided to you.

  3. Apply a bead of latex caulking or use a plumber's putty product to line the underside of the hole. This will help hold the undermount sink in place. Position the sink on top of the hole.

  4. Place the undermount sink into place and hold there while tightening the mounting screws into place. Clean any exposed caulking if it squeezes out after all screws are tightened into place. Use only those screws provided to you by the undermount sink manufacturer.

  5. Position the faucet into place and attach it to the underside of the sink as directed by the manufacturer. Install the drain assembly that runs from the sink's hole to the bottom of cabinet. Push it into the drain securely then tighten the lock nut at the top to hold the drain into place. Install the S trap and drain pipe to the bottom of the sink.

  6. Give the undermount sink at least 18 hours for the caulking to dry before running water through it. Once dry, look for leaks and handle immediately by tightening the pressure couplings slowly.