Informational Guide

Undermount Vs Overmount (Top Mount) Sinks

Bathroom & kitchen sinks come in all shapes, sizes, & styles. Here we compare the differences between the undermount vs overmount.

by Ian Haynes

Bathroom and kitchen sinks come in all shapes, sizes, and styles, which can make the sink-buying process feel overwhelming. And just as you thought the process of buying your sink couldn’t be more difficult, you discover that there are also different installation methods: undermount and overmount.

Deciding between under mounting and over mounting (also called top mounting or drop-in mounting) is all about comparing their differences and weighing each installation method's pros and cons. That's exactly what we'll be covering here in this complete guide to the top mount vs. undermount sink style.

Before comparing a top mount sink vs undermount sink, let’s cover the basics of each one, starting with the undermount installation method. Just as the name suggests, this type of sink is mounted from under the countertop or bathroom vanity surface.

Because they are mounted from below, the rim of the sink is hidden underneath the counter. Homeowners love the look of this since it gives off a clean, seamless aesthetic. In addition to being seamless, here are a few more pros of undermount sink installation:

  • Undermount sinks are highly customizable
  • Undermount sinks give more counter space since there is no visible edge
  • Without a sink edge, it’s easy to wipe messes directly into undermount kitchen sinks
  • Undermount sinks are best for deeper cleaning of large pots and pans

But just like anything in the world of plumbing, under mounting a sink also has its cons, including:

  • They require more support since they don’t have the countertop to carry their weight
  • Undermount sinks are usually more expensive
  • They are more difficult to install/replace
What Are Undermount Sinks

What Are Overmount (Top Mount) Sinks?

Overmount sinks, AKA top mount or drop-in, are mounted from the top of a countertop, literally “dropping in” place to sit securely on top of the surface. With this installation method, the lip or rim of the sink is visible from above.

There are several pros to this sink style:

  • Top mount sinks are versatile and come with single and double bowls (and even triple!)
  • They are easy to install since they just drop into place from above the counter
  • Overmount sinks are cost-effective, both upfront and for installation

Most homeowners agree that the main drawback of top mounting a sink is the lack of a “seamless” look since the sink’s rim is visible. Here are a few more cons to consider before choosing a top-mounted sink:

  • Top mount sinks require heavy countertops since they rest on the surface
  • Top mount sinks take up more counter space than undermount sinks
  • The sink rim on the surface creates a barrier when cleaning countertops (crumbs can become lodged beneath the edge)
What Are Overmount Sinks

Undermount vs. Overmount Sinks: Key Differences Explained

The key difference between an undermount sink vs. overmount sink all comes down to the way it is installed. One is installed from below the surface of the counter (undermount), while the other is dropped into place from above (overmount).

That's not the only significant difference worth noting, though. Another one is that undermount sinks are preferred by many for their seamless design, but then you have to take into account the fact that this style is more difficult to install than top mount sinks.

Then there's the difference in the cost of an undermount sink vs. a top mount sink. Undermount sinks tend to be more expensive up front, and there's also a price difference between top mount vs. undermount sink installation. Plumbers usually charge more for under mounting since it's a more difficult process and requires more support from below the counter surface.

The last key difference to consider has to do with cleaning and maintenance. With topmount sinks, keeping counters clean can be more challenging since the sink rim prevents you from wiping messes directly into the sink basin. With undermount sinks, there’s no rim to get in the way, therefore making it easier to clean the countertop.

Undermount Vs Overmount Sink

Which Type Is Better for Bathrooms?

When comparing overmount vs. undermount bathroom sinks, it's really impossible to say which is better. While one homeowner is all-for the sleek undermount style, another might be gung-ho on easy topmount installation.

As mentioned earlier, there are pros and cons to both styles, so it all comes down to personal preference. It depends on what you value most - do you prefer a seamless bathroom aesthetic, or would you rather find an affordable sink option for sticking to a renovation budget?

The good news is that you can’t go wrong with either; there are plenty of quality options on the market for both undermount and overmount sinks.


People Also Ask (FAQs)

Which of the two are easiest to keep clean?

Undermount sinks are without a doubt easier to keep clean. Top mount sinks have a rim that sits above the counter surface, so it’s not as easy to wipe countertop messes directly into the sink.

Can I convert an undermount sink into a drop-in sink?

Yes! Even as you browse around for sinks, you’ll notice that many of them say “suitable for both top mounting and under mounting” in the product description. Here’s what Doityourself.com has to say about under mounting a drop-in sink (or vice versa):

“Despite much disapproval from sink experts that drop-in sinks are impossible to undermount, the job is actually possible. There are a lot of people out there who love the look of their drop-in sinks, but also want to have an undermount sink design for their countertops. Usually, undermount sinks are used for this purpose; however, a drop-in sink can also be placed under the countertop to fit it like an undermount sink.”

Can I replace a top-mount sink with a drop in an undermount sink?

Yep, just as it’s possible to replace an undermount sink with the drop-in style, you can do the same the other way around. Just pay close attention to the sink dimensions - it’s vital that you find a sink to match the hole that’s already in your countertop so that you don’t have to make any major alterations.

Can you replace an undermount sink without removing the countertop?

There’s no need to remove the countertop, especially if you have a professional plumber completing the task. These sinks are mounted from below the counter and held into place with mounting clips, typically while the countertop is still installed.

Do undermount sinks leak?

When installed properly, no, your undermount sink will not leak. High-strength epoxies and silicone caulk line the area where the sink rim and the countertop meet, and both are very effective for preventing leakage.

Can you use an overmount sink with granite?

Yes, it’s possible to install an overmount sink within a granite countertop. However, granite is a very expensive material, and because overmount sinks take away from some of the counter space, many homeowners opt to undermount their sinks if they have granite counters.


Conclusion

There’s no right or wrong answer to the “undermount or overmount?” question. Before you make your purchase, just be sure to weigh the pros and cons of each and compare the key differences between the two.

Ian Haynes is an expert writer who has successfully deployed over 500 plumbing pages and other related content. He has an excellent understanding of home plumbing issues and translates his experiences via Plumbing Lab so readers can have a better understanding of common household problems. Outside of his work, Ian likes exploring Brooklyn with his Labrador.

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