How to Install an Under the Counter Kitchen Sink

Under-the-counter kitchen sinks are becoming increasingly popular because of the sleek look they offer and the variety of styles and materials in which they appear.

These sinks are also convenient for prep work because they make for simple clean up and food does not get caught in the lip of the sink. They are a little more complicated than conventional sinks to install because it involves a little more than dropping a sink in place. This style works best with stone countertop surfaces, because they are strong enough to hold the sink. It is possible to install an under-the-counter kitchen sink yourself and it takes a few basic tools.

Choose the correct sink for your countertop. Make sure the sink will fit in the space and there is enough room underneath the sink. Check that the water lines and drain pipes can reach the new sink.

Hire a professional to cut the stone countertop, buff the openings for the sink and faucet and drill holes for the clamps to secure the sinks. Do not attempt to cut the stone countertop yourself unless you are experienced, because it is expensive to replace. Provide the professional with the paper template the manufacturer supplied for the sink.

Using a wire brush and rubbing alcohol, remove any dust particles from underneath the sink and openings that were left over from the cutting. These particles must be removed or the sink may not fit properly.

Flip the countertop upside down when you install the sink. Place a soft cloth underneath it to prevent scratches. Set the sink over the hole and trace an outline with a marker where to place the silicone putty.

Add a thin line of silicone putty around the lip of the sink and push it into the under side of the counter, using the outline you drew as a guide.

Mix together two-part epoxy that you will apply to the screws near the sink lip. Use a pipe wrench to tighten the nuts on the bolts. Let the epoxy dry for 24 hours, which will ensure the clamps do not come loose.

Apply silicone putty to the sub surface of the countertop. Place the countertop over it.

Attach the drain basket by adding a thin line of silicone putty to the edge of the drain hole of the sink. Push the basket in place. Add the rubber gasket and locknut to the end of the basket and tighten with a pipe wrench.

Place a metal nut on the end of the tail pipe and place a plastic washer over it. Use a pipe wrench to tighten it to the sink basket. Connect the P-trap to the tail pipe with nuts and hand tighten.

Things You Will Need

  • Under-the-counter sink
  • Wire brush
  • Rubbing alcohol
  • Marker
  • Silicone putty
  • 2-part epoxy
  • Pipe wrench
  • Cloth


  • Make sure to turn off the water supply underneath the sink by shutting off the valve.
  • Enlist the help of another person when carrying the countertop, because it can be heavy.
  • If you do decide to cut the countertop yourself, you will need a saber saw and a keyhole saw to smooth out the edges. Use the template for the sink to cut along the edges. Always wear goggles and a mask to protect your eyes and lungs from dust particles.