Undermount Sink vs. Drop-In Sink: Product Comparison and Contrast

While the world of kitchen sinks is large and varied, for most homeowners doing a kitchen remodel, the field narrows down to just two major configurations: drop-in or self-rimming sink or undermount sink.

When undermount sinks first hit the consumer market, they were expensive and considered difficult for pros and do-it-yourselfers alike to install. But now that professionals are just as comfortable installing undermount sinks as they are with drop-ins, and prices of undermount sinks have become more competitive, the choice is that much harder.

What a Drop-In Sink Is

A drop-in sink, also known as a self-rimming sink or top-mount sink, is installed by resting the sink into a hole in the countertop. The sink sits on top of the countertop and is held in place by a rim or lip that sits around the edge of the sink and rests on the countertop. Below the countertop are clips to hold the sink firmly in place.

Drop-in sinks are a popular choice for do-it-yourself homeowners because they are relatively easy to install and can be used with a variety of countertop materials. They are also typically less expensive than undermount sinks.

One drawback of drop-in sinks is that they may be more difficult to keep clean because the lip around the edge of the sink can collect dirt and grime. Additionally, the rim of the sink is visible when looking at the countertop.

On the whole, drop-in sinks are a practical and budget-friendly choice for many homeowners across a wide variety of kitchen styles.

What an Undermount Sink Is

An undermount sink is installed from underneath the countertop, rather than on top of it. This means that the edge of the sink is attached to the underside of the countertop, rather than sitting on top of it like a drop-in sink.

Undermount sinks are a popular choice for many homeowners because they offer a sleek, seamless look that is easy to keep clean. Because there is no lip around the edge of the sink, it is easier to wipe debris directly into the sink, rather than having to clean around the rim of the sink.

Undermount sinks are typically installed with special mounting clips that attach the sink to the underside of the countertop. The sink is then sealed to the countertop with a silicone caulk to create a watertight seal. Because of the precision required for installation, undermount sinks may be more expensive to install than drop-in sinks.

Overall, undermount sinks are a popular choice for many homeowners because of their modern appearance. But it is important to consider your budget and installation needs when deciding which type of sink is right for you.

Countertop Space: Undermount Sinks Win

With undermount sinks, the countertop extends all the way to the sink—even a bit more. If you're tight on room and need every possible square inch of counter real estate, undermount is the way to go.

However, there is one type of drop-in sink that can save some counter space: the drainboard sink. This has an integrated drainboard and/or food prep area that extends 8 to 10 inches beyond the side of the sink basin. If you're tight on counter space, this counterintuitive move—adding more sink rim instead of less—might actually be more economical on space.

Sink Cleaning: Drop-In Sinks Win

One of the more frustrating things about undermount sinks is the gap at the top of the sink, where it joins up with the counter. While this gap is filled with a bead of silicone caulk, it's usually not filled flush to the surface. A depression remains, and this naturally becomes a magnet for food buildup. Citing this issue, Greg Fox at Fox Granite Countertops recommends digging out the caulk and replacing it on undermount sinks every three to five years.

With drop-in sinks, all working areas of the sink are visible and accessible. However, it should be noted that the small, visible seam formed by the lip and the countertop can build up gunk as well. The only difference is that you have better access and more visibility when cleaning the drop-in sink.

Counter Cleaning: Undermount Sinks Win

The clear winner in the category of countertop cleanup is the undermount sink. In fact, ease of cleaning is the number one selling point of the undermount configuration. Because there is no lip to form an obstruction around the sink, you can swipe food particles directly off the counter and into the sink. 

Some drop-in sinks have lower-profile rims than others, making it easier to swipe from the counter into the sink, but it’s still nothing like the seamless undermount experience. Stainless steel drop-in sinks tend to have the lowest rims, while enameled cast iron sinks have a tall rim that you have to swipe around, not over.

Installation: Drop-In Sinks Win

Homeowners can install a drop-in kitchen sink on their own as long as it is a one-for-one replacement. After cleaning away any old caulk, lay down a bead of caulk, set the sink into the hole, center it, and secure it with clips underneath the countertop.

While an exact replacement in size is generally easier, there are things to consider. Removing the old sink is not always an easy task. There is potential damage to the countertop that can occur. The depth of the sink needs to be considered, too. This can result in having to alter the plumbing drain connection below the sink.

By comparison, undermount sinks require much more care for proper installation. They must be fitted in place and supported temporarily while the clip locations are marked. Holes must be drilled into the countertop (very carefully) and the clips installed. Then the sink must be caulked and mounted—with almost no room for error.

Undermount sinks typically are recommended for all countertop materials except laminate (they can also be problematic with custom tile countertops). The laminate isn't the issue; it's the underlying base of particleboard or MDF. MDF does not hold clip fasteners well, and it is highly vulnerable to moisture damage. It’s possible to cover the sink-hole edge with laminate to protect the MDF core, but the seal between the sink and the laminate must be flawless to keep water away from the MDF.

By contrast, drop-in sinks can be installed on all types of countertop materials, including laminate, tile, solid surface, and all composite and natural stone.

Cost: Drop-In Sinks Win

Drop-in sinks are typically less expensive than undermount sinks. This is because drop-in sinks are designed to be installed by simply resting them into a hole in the countertop, a relatively easy process.

In contrast, undermount sinks require more precise installation, as they are mounted underneath the countertop and need to be securely fastened to the underside of the counter.

Resale Value: Undermount Sinks Win

Whether your kitchen has a drop-in sink or an undermount sink will not, by itself, change the resale value of your home. Resale value is affected more by major upgrades, such as additions, whole-house flooring, or finished rooms, than by single elements like a kitchen sink or bath vanity.

That said, undermount sinks clearly have a more custom, high-end look and feel compared to conventional drop-ins. As one building block of a highly valued designer kitchen, the undermount sink can be said to impart higher value to potential buyers than a drop-in sink.

Which Sink Is Best: Undermount or Drop-In?

Whether an undermount sink or a drop-in sink is better for you will depend on your specific needs and preferences. Consider these factors when deciding which type of sink is right for you:

• Installation: Undermount sinks typically require more precise installation than drop-in sinks.
• Countertop: Undermount sinks can be used with a variety of countertop materials, including granite, quartz, and solid surface. Drop-in sinks, on the other hand, are generally more flexible and can be used with any type of countertop, including laminate and tile.
• Appearance: Undermount sinks offer a sleek and modern look, while drop-in sinks have a low rim that may be visible.
• Cleaning: The lack of a rim around the edge of an undermount sink makes it easier to brush food directly into the sink.