Undermount Kitchen Sink vs. Drop-In Kitchen Sink

Although there can be very many different ways to remodel a kitchen sink, for most homeowners, they mostly consider two types when doing a kitchen remodel: drop-in and undermount. But many times they look similar and make it hard to choose, so what's the difference between them? What are the advantages and disadvantages of each? Read on to learn more about these two types of sinks so you can decide which sink option is right for you. Choosing between undermount or drop-in can basically come down to personal preference, but this decision should be made during the design phase, as this choice affects countertop materials and installation.

The earliest sinks were basins that sat on a shelf, and today, most modern sinks are still essentially basins attached to the countertop, from below (undermount) or from above (drop-in).

Undermount sinks are relatively new, having only become commonplace in the last 60 years or so. When undermount sinks first entered the consumer market, they were expensive and considered difficult to install. But now, professionals are just as comfortable installing undermount sinks as they are installing drop-in sinks, and undermount sinks have become more competitively priced as technology has improved, making the choice even harder for users.

What is a drop-in sink?

Drop-in sinks, also known as self-rimming or top-mounted, are still the most common type of kitchen sink. A drop-in sink has a distinct lip around the perimeter and sits flat on the countertop. The sink basin falls directly into the countertop cutout, and the lip around the perimeter holds everything in place.
Drop-in sinks are held in place by metal clips hidden under the countertop and by silicone caulk under the sink rim.

What is an undermount sink?

Undermount sinks are installed on the underside of the countertop and are held in place by heavy-duty clips and caulk or special adhesives. An inset sink does have an edge, but the edge is not visible because it rests on the bottom of the countertop. The edge of the countertop along the sink cutout is completely exposed. For this reason, inset sinks must usually be used with solid countertop materials such as solid surface, natural stone or quartz that can be polished and sealed.
With an undermount sink, the countertop extends all the way to the sink and a little more, so an undermount sink gives you as much countertop space as you need.

Differences between the two (combining some aspects on the advantages and disadvantages of both)

Sink cleaning

With a drop-in sink, it's easier to clean the sink. This is because all the working areas of the sink are visible and accessible. Of course, it should be noted that the small visible crevices formed by the lip and the countertop can also accumulate waste and need to be cleaned with care.

And one frustrating aspect of the undermount sink is the gap where the top of the sink meets the countertop. Although this gap is filled with silicone caulk, it is usually not flush with the surface. A depression remains, which makes it very easy for food to accumulate. Based on this problem, it is recommended that the caulk be dug out and the undermount sink replaced every three to five years.

Countertop Cleaning

When it comes to countertop cleaning, undermount sinks in turn are superior. In fact, the ease of cleaning is a major selling point for undermount sinks. Because there is no lip around the sink to form an obstruction, you can sweep food particles directly from the countertop into the sink.

Some drop-in sinks are designed with edges as low as possible to make it easier to sweep from the countertop into the sink, but it's still not as seamless as it could be. Stainless steel drop-in sinks tend to have the lowest edges.

Installation

Drop-in sinks are installed from above, while undermount sinks require enough space to install from below. Other than that, the basic concept is the same. Mounting brackets hold the sink to the countertop and seal the transition from the countertop to the sink with caulk.

The biggest installation difference involves the objects around the sink. Countertops must be prepared differently for undercounter sinks and drop-in sinks. As mentioned above, undermount sinks require a higher level of finish for the hole edges. And faucets and fittings require access holes drilled in the countertop. For these reasons, it is rare, though not impossible, to switch between these two installation systems during a renovation.

Alternatively, with the same size replacement, homeowners can perform their own installation of a drop-in kitchen sink: after cleaning off any old caulk, lay down a layer of caulk, place the sink in the hole, center it, and secure it with clips under the countertop. Of course removing an old sink is not always an easy task. There can be potential damage to the countertop.

In contrast, undermount sinks need to be installed with more care. They must be installed in place and temporarily supported while marking the clamp locations. Holes must be drilled in the countertop (very carefully) and then the clamps installed. The sink must then be filled and installed with little room for error.

Cost

While undermount sinks are typically more expensive, it's the countertop that drives the cost, not the sink itself. The solid surface countertop construction required for undermount sinks means they are associated with higher-end kitchens, although the sink itself costs about the same.
The savings on drop-in sinks can be even greater if you choose to install them yourself. However, undermount sinks are not recommended because you can easily damage an expensive countertop if you make a mistake.

The following is a summary of the pros and cons of undermount and drop-in sinks

Pros of undercounter kitchen sinks:

• Neat and tidy appearance.
• Easy to clean the countertop.

Cons of undercounter kitchen sinks:

• Must be cleaned or caulked.
• Requires a solid countertop.
• Requires a perfect opening in the countertop.
• Higher price.

Pros of drop-in kitchen sinks:

• Can have a rough opening.
• Traditional look.
• Easy to recaulk.
• Easy to clean the sink.

Cons of drop-in kitchen sinks:

• Slightly difficult to clean countertop.
• May not have a "high-end" look.