10 Step: How to Install Undermount Sink

I hope you are familiar with the undermount kitchen sink type. Unlike the another sinks, this is present in the basin or countertop and hangs-underneath the surface effectively.

Suitable Materials for Made Kitchen counters

Install Undermount Sink
  • Granite
  • Concrete
  • Soapstone
  • Marble

In the case of tiles counter, it’s a best practice to use this type of sink as there are too many seams and it may not be able to bear the sink weight. It is not only easy to clean but attractive in style. It does not let dirt accumulate into the rim area, as there is no exposed rim in first place.

Though this type has many advantages, the drawbacks are its slightly higher cost and the fact that you have to attach the faucet on the wall overhead. Its price ranges from $250 to $800.

How to Install Undermount Sink Step by Step


In this post, I have discussed the guide on how to install undermount sink. Its installation is a bit difficult, as you have to make sure the sink fits in properly and there are no leaks or breaking apart once it is in place. 

The undermount sink can fit in the sink in the following configurations:

  • Positive Reveal: Defined as a flush mount – where the countertop area is actually flush with the inside of their sink therefore do not witness any reveal show. This might be harder for a fabricator to achieve since it has to be an exact cut to the side of a sink.
  • Zero Reveal: The countertop edge sits back once again through the edge of the sink, exposing a small part of the sink rim. This might be easier for the fabricator because they have a small total of leeway in the cut.
  • Negative Reveal: The countertop extends over the top edge of their sink upon all sides.

Things You Will Need for Install Undermount Sink

  • Cutter
  • Marker
  • Caulk
  • Drill bit
  • Tape measure
  • Safety glasses
  • Denatured alcohol
  • Gloves
  • Caulk gun
  • Drill
  • Jigsaw
  • Screw gun
  • Sawhorse
  • Masking Tape
  • Fitted teak countertop
  • Clean cloth
  • Silicone caulk
  • Undermount sink with mounting hardware

Step 1: Record Some Measurements

For the first step, you need to call in a professional as handling the undermount sink is not an easy task. You have to take the measurement of the sink and draw a square shape on the granite or any other material counter. A professional can easily cut the hole according to the dimensions.

Others step are easier to handle and you can follow DIY rule. However, I would suggest that you call in a plumber for drilling in the hole for in the counter for you. This is the place where you will insert the sink.

Step 2: Take Hole Markings

Once the hole is there, place the undermount sink inside it. This is to check whether the sink fits in perfectly or not. Now mark the places where you need to drill holes in the countertop.

Step 3: Drill The Holes

Take out the sink and drill holes in the countertop using a drill machine. In these holes, you will insert brass holdings. Before that, take a rag cloth and dab some denatured alcohol on it. Use it to clean the ridge of the counter surface and the sink. Let it dry before continuing with your work.

Step 4: Coat The Silicone Sealant

Use a silicone gun to eject silicone sealant in a thick, single-line stream on the rim or lip of the sink. Insert it in place inside the countertop from below and make adjustments so that it is in the exact center.

Step 5: Clamp The Sink

Now place a 2×4 spanning the frame of the sink from the top. You have to clamp the sink. One end of the clamp will pass the underside of the sink through the drain hole and the other will be on top of the 2×4 wooden-plank.

Next, you have to make the tightening connections. Thus, before that make sure that the sink is in its correct position and it won’t fall out of the hole.

Step 6: Insert The Brass Clips

Now, you see the holes you had drilled in the countertop. These are for brass inserts. Brass insert is the other name for the anchor that holds the sink in its place. Now insert each anchor in its hole with the slotted end going in first.

Step 7: Secure The Brass Clips

Now prepare an assembly of the screw, washer, slotted clip and wing nut. This you will use to mount on the brass insert to keep it in its place. Do this for all the brass clips/inserts. Tighten the nuts manually or use a screwdriver to secure them.

Step 8: Clean Off The Sink

After you have made the wing nut connections, you will use masking tape. Stick it to the backside of the counter. Let the sink dry first. The silicone sealant you have used to plaster the sink to the countertop takes some time to dry. Therefore, it will be better if you install the faucet and water lines after waiting a few hours or a day. Wipe off the excess sealant using a cloth. If the sealant has dried up on the outside, cut it carefully using a putty knife.

Step 9: Install The Faucet

Once the installation of the sink is complete, install the faucet in the countertop. You cannot install the faucet directly on the undermount sink; either it is on the wall or on the counter surface. Make the water connections of the faucet as I have guided you in my other posts.

With this step, you are almost done with your work. The only thing left is to run a check on the newly installed sink setup.

Step 10: Perform The Final Check

The best practice is to perform a check always, as it is wise to detect and solve a problem while you are at work. When you have finished the installation of your undermount sink in the kitchen, turn the faucet handle. The water will flow out and run down the sink drain. Try loading some dishes into it. If everything is fine, the sink will remain intact and bear the weight of dishes. If, unluckily, it comes out, you will have to start the process over but carefully this time. Check out another information how to install Pedestal sink.


I hope you enjoy reading this guide and it turned out that installation of an undermount sink is not as difficult as you were expecting it to be. If you are careful enough, you can even drill the hole in the counter yourself. Spread the information ahead and provide me with your useful feedback.