Can You Replace an Undermount Sink Without Removing the Countertop?


Undermount sinks give more functionality in terms of cleaning dirt from the countertop surface. However, because they are placed in a countertop opening, the installation looks permanent. Thus, there is common confusion about whether or not they can be replaced without removing the countertop.

More so, most solid surfaces like granite are prone to breakage at the slightest fall. If you would like to replace a sink without replacing the countertop, this guide will be helpful. In this article, I will be answering that question for all countertop types.

Replace an Undermount Sink Without Removing the Countertop

Is it Possible to Replace an Undermount Sink Without Removing the Countertop?

There are no direct answers – it all depends on the countertop type. It is not as easy as removing bolts and adhesive sealants as many people think.

Undermount sink countertops are either made of a solid surface or a laminate surface. Even though both have similar functionality, their installation and repair processes differ.

For solid surface countertops (be it Quartz, Marble, or Granite), you can replace the undermount sink without removing the countertop.

Structurally, a solid countertop can stay in position with or without the undermount sink. Usually, all solid surface countertops are fastened to the stone with epoxy from under.

Laminate countertops, on the other hand, are installed on a wooden platform beneath the laminate surface.

Because of the laminate countertop’s support system, it may be difficult to remove the undermount sink with the countertop in position. In removing an undermount sink with a laminate countertop, there might be a need also to remove the laminate surface.

Can an Undermount Sink Be Replaced?

Absolutely, yes. You can replace an undermount sink with or without the countertop. However, it might be difficult getting another sink with the exact dimensions of the existing one. Sometimes, they are not stocked in retail shops. But in this case, there are two options for getting a perfect fit for the opening.

First, locate the manufacturer. If the undermount sink type is still in the market, you order directly from the manufacturer. Suppose the manufacturer no longer produces the specification. Here is another alternative. Hire someone to fabricate a new stainless-made sink with the opening dimensions. It would be best if the sink maker measured themselves to avoid mistakes.

How Hard is it to Replace an Undermount Sink?

Two factors influence how easy or difficult it is to replace an undermount sink. The first is the connection between the sink and the support. It is pretty easy for a sink with a clamp.

All that is required is to loosen the clamps and strip the sealants around the edge of the sink. It could be more difficult with undermount sinks resting on a sub-base or the cabinet walls.

The other factor is finding a new sink with exact opening and material specifications. A locally-fabricated stainless sink may not fit into a luxurious space.

How to Replace an Undermount Sink Without Removing the Countertop?

If you are not removing the countertop with the sink, there’s a need to be careful, so it doesn’t get damaged. Below is a step-by-step guide for the process.

Step 1: Get the Tools Required

The first step to getting it right with an undermount sink replacement is to have the right tools in the box. Here’s a list of items you need.

  • Measuring tape
  • Tongue-and-groove pliers
  • Utility knife
  • Screwdriver
  • Razorblade
  • Denatured alcohol
  • Silicone sealant (the 100% silicone type used for attaching kitchen sink to countertop)

Step 2: Get a Replacement Sink

In choosing a replacement for your undermount sink, consider the design/type, color, and dimension. You can measure the length, width, and depth with your measuring tape. It is no problem if the depths of the existing and new sinks are different.

What is essential here are the length and width. That said, you do not need the exact figures. Your measurement is only to have an idea of what will fit into the existing opening.

Step 3: Remove All Existing Connections

Now that you have another sink and are ready to start the replacement, remove all the existing connections.

To remove the P-trap, loosen the slip nut and carefully unplug the trap from one of the ends. It would be best if you remove the garbage disposal end first before the drain tailpiece. Going the other way can lead to prolonged inhalation of sewer gases.

Following the same procedures, remove the drain tailpiece. With pliers, loosen the supporting nut and remove it from the drain pipe. Immediately after removing the drain tailpiece, cover the drainpipe with an old cloth, so sewer gases do not enter the room.

Step 4: Support the Existing Sink

After making all the necessary disconnections, support the existing sink before removal. The support will prevent the undermount sink from falling after disconnection from the countertop.

Place the 2×4 plank horizontally over the sink—next, wind enough wire around it (not less than seven rounds). Make a dowel with ¾-inch wood. The dowel should be about seven inches long. Now pass the other end of the wire wounded around the 2×4 plank through the sink’s drain.

Place the dowel underneath the sink and wind the wire around it. Keep winding until the dowel is well-held against the sink’s base.

Now, you can proceed to remove the sink without the fear of your undermount sink falling off.

Step 5: Unfasten the Hold-down Clips

With the 2×4 plank and wooden dowel around your undermount sink, loosen the clips connecting the sink to the support anchors. For this step, you need the screwdriver to unscrew hold-down screws. You can attempt removing the sink at this stage. If it is not disengaging, proceed to the next step.

Step 6: Strip the Adhesive

Depending on how fastened your sink is to the countertop, you may need to remove the sealant at the edges. Hold the utility knife carefully and cut through the adhesive above the sink.

You may need more than a pass to cut through the sealant. But ensure you don’t apply too much pressure, so you don’t damage the countertop.

After successfully stripping off the adhesive, your undermount sink will be disengaged, and you can carefully bring it down.

Step 7: Remove the Existing Sink

To remove the sink, gently pull vertically downwards. The wire around the dowel will unwind, and you can safely remove the sink through the cabinet.

Step 8: Prepare the Space for the New Installation

Scrap the remaining old sealant away from the surface and clean it with an old cloth and some denatured alcohol.

Step 9: Install the New Sink

Finally, lift the new sink and clamp it to the support anchor. Before applying adhesive around the edges, make support with two pieces of 2×4 planks.

Alternatively, get someone else to hold the sink into position. Once the new sink is well seated, neatly apply silicone sealant around the edges. You can wipe any excess sealant with an old cloth.

Step 10: Reconnect the P-trap and Drain

Finally, reinstall the p-trap and connect it to the drain. However, allow the sealant to dry properly before reconnecting the trap and using the sink.

Can You Remove an Undermount Sink from Granite Countertop?

Can You Remove an Undermount Sink from Granite Countertop

If you have a granite countertop, it is possible to remove your undermount sink without affecting the granite.

However, because granite countertops are somewhat fragile, there’s a possibility of breakage. Suppose your undermount sink is under the cabinet walls. You need to lift the countertop, and that exposes the granite slab to some risks. If you are going DIY, we’ll recommend consulting a granite professional.

They will suggest helpful ideas to uninstall your undermount sink without breaking the granite top. Another idea is to get two persons to lift the countertop while bringing down the undermount sink.

Can You Replace an Undermount Sink Without Removing the Quartz Countertop?

Definitely, yes. You can replace an undermount sink with a quartz countertop. Unlike granite countertops, quartz countertops are less prone to damage. First off, disconnect all plumbing connections to the undermount sink. Afterward, remove the clips holding the sink to the quartz countertop.

Now cut through the adhesive at the edges. If it is an old sink, the adhesive may be too strong to break. Adhesives get stronger with time. Once you strip off the sealant, lift the countertop, remove the old sink and install the replacement.

Are Undermount Sinks Easy to Replace?

The procedures for replacing undermount sinks are pretty straightforward. You do not need to be a professional to get on the job. Although, it can be easier having the right tools and some plumbing DIY experience. All the steps in the guide above are DIY-friendly.

However, if you encounter any difficulty, you may want to seek on-the-job advice from a professional. Regardless of your skill level, it would also help if you had one or two people assisting you. Besides easing the job, it will be less time-consuming.

Also, have someone around to help you pick tools and lift the countertop.

Can You Replace an Undermount Sink Without Damaging the Granite?

Absolutely, yes! Start by removing the p-trap and other plumbing connections from the sink. Following the processes described earlier, make a support for the sink.

Where you need to be careful is how you remove the clamps connecting the sink and the granite countertop. Loosen the clamp’s screw and sever the adhesive-joined edges.

Now have someone gently lift the granite countertop while you bring the undermount sink down through the cabinet. Follow the same approach in reverse to install the replacement sink. If you are careful, you won’t need an undermount sink replacement granite countertop.

Can You Replace an Undermount Sink With a Farmhouse Sink?

With some cuts in the cabinet, a farmhouse sink will make a suitable option for an undermount kitchen sink replacement.

However, there is a need to confirm that the cabinet is strong enough to carry the heavyweight of the new sinks. To provide enough structural support, you may need to install wooden support beneath the farmhouse sink.

The support will serve as a platform for the sink, so there won’t be too much load on the cabinet. Before ordering the new sink, measure the dimensions of the existing opening to know what size to shop for.

Conclusion

It is possible to replace an undermount sink without removing the countertop. But before getting into the DIY spirit, ensure you have the right tools.

Also, measure the existing opening ( length, width, and depth) before the new installation. This will give you an idea of what sink size will fit perfectly into the space.

Depending on the type of countertop, its size, and your expertise, you may need helping hands to lift the countertop while removing and replacing it.

Sometimes, seeking the input of an experienced DIYer or a professional can be necessary. It will help you make informed decisions and possibly adjust the guide to suit your project specifics.

Lisa Burks

Hi, I'm Lisa Burks, founder of the Sink Formula blog, and plumber of 5 years experience.

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