How to Install an Undermount Sink in a Wooden Countertop

Knowing how to install an undermount sink for wooden countertops is important to completing your butcher block or teak countertop dream.

Wood counters are striking to look at, easy to care for and relatively inexpensive. Though you may worry that wood and a wet sink spell disaster, there’s good news.

As long as a wooden counter is sealed with a food-safe, waterproof finish, it can be the perfect home for any sink.

An undermount sink can especially improve the functionality and style of a wood counter top if installed correctly.

Things to Consider When Installing an Undermount Sink

Undermount sinks utilize adhesive sealant, brackets and caulking to hold it in place. When installing the sink in a wooden countertop, the sink’s attachment brackets should be invisible when viewed from above.

Extra care should be taken to fully seal the area where the sink and counter make contact. Moisture or leaks can easily be prevented with the proper caulking procedures.

Care should also be taken to use silicone caulking in addition to undermount brackets, which are also called clips.

Unlike granite or stone, wood counters sometimes cannot handle the weight of a large sink with brackets alone. The following steps should help you to properly install your undermount sink in a wood cabinet.

Materials You Will Need:

  • Handsaw
  • 1×2 inch pine planks
  • Silicone caulking/adhesive
  • Caulking gun (optional)
  • Measuring tape
  • Three to four sink clips with screws
  • Drill with screw-head attachments

NOTE: Though not necessary, it may be helpful to have someone assist you.

7 Steps to Install an Undermount Sink in a Wooden Countertop:

1. Measure and Cut Support Beams

To properly install, you will need support beams to hold your sink steady after you lift it into place. For this reason, you must cut wooden planks to custom size ahead of time.

Step 1:

First, measure the area. Start by measuring the distance between the bottom of your counter top and the floor of your cabinet.

Then measure the distance from the top of your sink to the bottom of the bowl. Take the second number and subtract it to the first number to get the height of your support planks.

For a quicker measuring method, ask someone to help. Place one hand in the sink drain from above and place your other hand on the bottom of the sink from below, and lift the sink up until its flush with the counter hole.

While holding the sink in place, your helper can measure the distance between the floor and the bottom of the sink bowl.

Step 2:

Cut the planks down to size. Use pine instead of plywood or plastic. You want these supports to securely hold the weight of your sink. Cut at least two. Set aside.

2. Apply Silicone Sealant

Step 1:

Place your sink on the ground near your counter top. If you are using a caulking gun, go ahead and load it with your tube of sealant. A caulking gun can offer a more consistent, even application, but squeezing the tube manually works too.

Step 2:

Place a generous line of silicone sealant around the top edge of the sink lip on the side that will sit against the underside of the counter. Don’t worry about applying too much. You will be able to easily remove any excess once this dries.

Step 3:

Reach through the hole cut into the counter top and lift up the sink until its rim makes contact with the underside of the counter top hole.

Line up the edges of the hole to the rim of the sink. The edge of the counter top hole and the bowl of the sink should be one continuous line.

Be sure to make these surfaces as flush with one another as possible. Be sure to do this while sealant is still wet and pliable.

3. Place Support Planks Under Sink

Step 1:

Once the edges of the sink rim and counter are aligned, take your custom-cut support planks and prop them up under the bottom of your sink at even distances.

For extra security, have a helper place the planks while you keep holding the sink in place. The sink should be evenly balanced on these boards.

Step 2:

Make sure the supports underneath fit nice and tight, as a snug fit will exert upward pressure onto the sink. This pressure will ensure the silicone on the lip of the sink will bond securely with the underside of the counter top.

Step 3:

Because of possible sliding due to wet silicone, double check the alignment of the sink lip and the counter top after you have placed the planks under the sink.

Adjust as necessary, being careful that the pine planks hold tight. Leave to dry according to the time recommendations on the sealant bottle.

4. Clear Away Excess Sealant and Caulking Material

Step 1:

After sealant has dried, examine the edge where your sink and counter top meet. If there is any excess silicone material, feel free to clear it away with a dull putty knife.

Step 2:

If there are flanges that are unable to be cut away, take some sand paper or small nail file and buff the edges smooth. Be sure to take your sink’s finish into consideration when doing this. Avoid scratching or marking your sink’s interior.

5. Install the Undermount Sink Brackets

Step 1:

Working from below, eyeball where you wish to put your sink brackets. These should be spaced apart at an even distance to provide maximum hold and support. Usually a clip on each corner of the sink will suffice.

Step 2:

Place the bracket so that one end is on the underside of your wood counter top. The other end of the bracket should be on the underside of your sink’s rim.

Step 3:

Plug in your drill or, if it is cordless, check the drill’s batteries. Drill the bracket’s accompanying screw to secure the clip onto the surfaces.

You should be using at least one-inch screws for this process. You want screws that are long enough to hold everything in place, but not so long that they would be visible from above.

Step 4:

Work clockwise to keep a good sense of distance and progress. If you secure the top right corner first, for example, attach the bottom right bracket next.

Placing your brackets in this order will allow you to gauge distance from the last bracket and where the next one should go.

6. Seal Any Gaps

You should not see any major gaps between sink and wooden counter, as everything should fit tightly together. However, there may be areas that are prone to minor stress with time and wear, such as near the handles or faucet areas.

Take your clear silicone sealant and fill in these areas. Allow to dry and buff away any excess. Doing so will seal the area and prevent any leaks.

7. Remove Support Planks

After your silicone has dried and your brackets are installed, your sink is ready to be plumbed properly. It will then be ready for use.


It should not be too challenging to set up an undermount kitchen sink to wood counters if the right steps are followed. Always make sure the edges of the sink and counter line up exactly.

Doing so will avoid any headaches in the future, such as trapped moisture or leaks. Also be sure the brackets are securely screwed in with no chance of coming loose.

There’s no harm in double-checking the tightness of the brackets every year or so. Normal wear and tear can occasionally jar or loosen a screw. It’s always preferable to check.

Most importantly, always be mindful to clean your sink and wood counter top regularly. Though wood counters can be durable and attractive, keeping them in good condition will ensure they’ll remain a sturdy area for your sink.

Likewise, avoid leaving heavy dishes or items in your stainless steel kitchen sink for long periods. Since an undermount sink is suspended from above, placing unnecessary weight on it may strain the sink clips over time. With common sense and care you should be able to enjoy your sink in a wooden countertop for a long time.

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