How to Remove an Undermount Sink (7 Best Steps)


The ability of quartz countertops to accommodate composite, cast-iron, and stainless steel sinks is among its top benefits. In addition to their aesthetic appeal, these sinks are immensely spacious and very useful.

How to remove an undermount sink

A top mounted sink’s flange can trap food and debris, creating an unpleasant experience for you.

With an undermount sink, you no longer have to deal with this problem. To dispose of all waste, simply wipe the quartz countertop and insert all of the material into the disposal bowl.

The problem comes in when you need to replace an undermount sink that has either become cracked or is too old.

If the sink is old or damaged, you may wonder if you can just take it out from beneath.

I would say that, yes, it is possible to remove an undermount sink without the help of a professional plumber.

Don’t worry! I will give the clear cut outline on “how to remove an undermount sink” in this post.

  • Before you take out any sink, including an undermount, make sure you unplug the garbage disposal and the plumbing.
  • If the sink is attached to the countertop with clips, then you will need to remove the clips from under the countertop.
  • Certain bathroom sinks may not have clips attached.
  • Last but not least, the final step is to break the silicone bond seal, which is not an easy task.
  • Getting this last step done on an undermount sink can be difficult because it’s glued to the bottom of the countertop with silicone.

It’s tougher to replace a sink if the quartz countertop is attached with construction adhesive or epoxy cement. I know this is rare, but it does happen.

As a result, please continue to read further for a detailed section on how to remove an undermount sink.

Make a Support For the Sink

How to remove an undermount sink

You don’t want to drop your undermount sink when you finally free it from the counter, because the materials can be heavy.

There is an option to support it from beneath, but you will probably find that the supports will interfere with your movement.

If you have removed the garbage disposal and sink drain assembly, it is a good idea to support it from the top. Just follow these steps:

  • Place a 2 by 4 lumber parallel to the front of the vanity over the rim of the sink.
  • You have to wrap a piece of 12-gauge wire around the 2 by 4 a few times and then pull it through the drain hole.
  • A minimum of 12 inches should be hanging under the sink.
  • I suggest wrapping the wire around a 3/4-inch wooden dowel which is between 6 and 8 inches in length.
  • It is necessary to wrap the dowel until it rests firmly against the sink base.
  • As soon as the sink is removed from the countertop, rotate the 2 by 4 in a slow motion so that it gently lowers.
  • By doing so, the wire will be untangled.

Materials Required

  • Screwdriver
  • Utility knife
  • Wood shims
  • Tongue-and-groove pliers
  • Bucket
  • Rag
  • Heat gun
  • Hammer
  • 2×4 lumber
  • 12-gauge wire
  • 3/4-inch wood doweling

Also read: How to Install Undermount Sink to Quartz in Less time

Step by Step Guide: How to Remove an Undermount Sink

Undermount Sink

I know it may seem obvious, but make sure that everything’s out of the sink cabinet before you start working.

Additionally, you will also need a light, such as a headlamp or portable lamp, in order to be able to see below the cabinet.

Step 1: Unplug the P-Trap assembly

  • A pair of tongue-and-groove pliers can be used to unlock the slip nut on one end of the trap, which is attached to the drain tailpiece or garbage disposal.
  • Next, you have to disconnect the other end from the waste trap arm, which was connecting to the branch outlet in the wall.
  • Carefully take out the trap because it’s soaked with water. Empty it outside or in a bucket.
  • After you have completed this step, take apart the remaining parts of the P-trap assembly.
  • Further, the drain pipe in the wall should be stuffed with a rag so that sewer gasses do not leak into your room.

Also read: How to Install Undermount Sink without clips

Step 2: Remove the Garbage Disposal

  • The disposal should be disconnected or unplugged depending on whether it is hardwired or not.
  • You should turn off the breaker before disconnecting electrical wires.
  • It is typically easy to remove a disposal by rotating the ring that keeps it attached to the drain opening with a screwdriver.
  • Once the ring has been rotated, the disposal can be removed. Place it safe aside.

Step 3: Take Out the Drain Assembly

  • Take off the drain tailpiece with the help of pliers.
  • Next, you will need to loosen the mounting nut of the drain assembly and then turn the nut counter-clockwise to remove the nut.
  • If you can, do it with your hands.
  • If the putty seal is difficult to loosen, you can knock the strainer upward with the help of a hammer.
  • Then you can lift the assembly out from the top.

Step 4: Remove the faucet (optional)

  • Undermount sinks generally feature a faucet that is mounted to the counter and does not require a separate removal of the faucet to remove the sink.
  • If you want to remove the faucet, then you must close the shutoff valves and then open the faucet.
  • This is done to release the pressure within the system.
  • You will now need to unscrew the nuts that secure the flexible supply tubes to the shutoff valves.
  • After that, you can easily detach the tubes.

Step 5: Ensure the Support for the Sink

  • The sink will need to be supported, either with 2x4s, wire, and dowels (described above).
  • Supports such as these are extremely useful for sinks made of cast iron, composite, or other heavy materials, however all sinks will benefit from this support.

Step 6: Remove the Sink Clips

  • In this step, you have to find the clips securing the sink to the support anchors.
  • Once you find the clips, you need to use a screwdriver to loosen the screws and remove them.
  • If time is favorable, you will be able to release the sink and you will be able to remove it easily once you have done this.
  • Still, it is more probable that there will be silicone or other adhesive added to the sink in order to keep it in place.
  • Furthermore, there are many bathroom sinks without clips that are attached to the vanity top solely by means of caulk.

Step 7: Slice the adhesive

  • Consider cutting the adhesive present between the sink rim and the countertop with a sharp utility knife.
  • Start from the top.
  • Breaking the seal will be easy with silicone adhesive.
  • In case there is another type of adhesive, such as construction adhesive or epoxy, you may want to contact a professional to prevent further damage to your countertop.

Also read: How to Cut Countertop for Sink

Wrap up!

I recommend cleaning the old adhesive off the countertop after you remove the sink, particularly if you plan on installing another undermount sink.

As part of the removal process, you may want to detach the anchors, which you can either do by loosening them or splitting them with a chisel.

I think it’s better to leave the anchors, if they are sealed in stone and fixed in place by epoxy, if they are coming in the line of sight, you can always cut them smooth with a hacksaw.

How to Replace an Undermount Sink (Video)

Frequently Asked Question

Can you replace an undermount sink without damaging the granite?

I think the short answer to this question is yes, you can replace it. In the event that you choose to do this yourself, I recommend consulting a granite contractor. Under the top, the sinks are secured with a strong adhesive. Most likely, this adhesive will need to be cut away and ground away from the underside.
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