Considering an undermount sink for your bathroom renovation? Then you’ve come to the right place.
This buying guide will tell you everything you need to know about undermount bathroom sinks.
We’ll talk about what makes undermount sinks distinct from other bathroom sinks, what the different types of undermount sinks are, and how to choose the right undermount sink for you. Then we’ll go over our top five picks for the best undermount bathroom sinks to help you narrow your options.
By the time we’re finished, you should have no problems picking out the perfect undermount sink for your bathroom.
Undermount sinks, also called undercounter sinks, are defined by how they’re installed. Both bathroom and kitchen sinks can be installed this way, but today we’re focusing on bathroom sinks.
In contrast, to drop in or vessel sinks, undermount installation involves attaching the sink to the bottom of the counter. This is done by applying caulk, silicone sealant, or another adhesive to a rim around the edge of the sink.
Then the sink is put in place underneath the counter, positioned so that the rim lines up with the edge of a cutout in the counter. Then clips are put in place to keep the sink in place.
The sinks should come with a mounting kit that includes all of the installation materials you need, such as adhesive, clips, and a template for the necessary countertop cutout.
Undermount sinks provide a sleek, contemporary look to bathrooms and are an excellent addition to any bathroom, from a master bath to a guest’s powder room. However, they’re also quite practical.
For example, they allow you to get away with a larger sink basin in the same space. For a drop-in sink, the outer edge of the bowl has to fit within the cutout in the counter, but with an undermount sink, the interior edges of the sink are directly underneath the edges of the cutout in the counter.
That gives you a bit of extra room inside the bowl.
In addition, the lack of edge on top of the counter means fewer tricky nooks and crannies on your countertops to have to keep clean. You can also just brush any messes on your countertop into the sink and rinse them down the drain.
We should also note the bathroom sinks don’t typically come with a faucet or drain, so you’ll need to buy those separately. Pop-up drains are typically the go-to for bathrooms and are available in all kinds of finishes, from shiny chrome to matte black.
The undermount sink style also means that the sink itself doesn’t include faucet holes, so you may need to have holes put in for a countertop or wall-mount bathroom faucet.
What Are The Different Types Of Undermount Bathroom Sinks?
Typically we’d categorize sinks by their mounting style, but since today we’re focusing on a particular mounting style, let’s instead look at shapes.
We can look at the shape of the rim and the shape of the actual basin.
The most traditional bathroom sink shape is the rounded, bowl-style basin that generally accompanies a circular or oval rim and there are plenty of undermount sinks that match this style.
But we’ve already mentioned that undermount sinks can give a bathroom a more modern appearance and a modern bathroom needs a modern style. For this, sinks with rectangular rims shine.
And they offer a greater variety of basin shapes.
For the most modern style, you can opt for a flat bottom basin, which is exactly what it sounds like. The sides of the basin may be straight down from the rim or slope down, but either way the bottom of the basin is flat.
For something in between, you can opt for a rectangular shape sink with a hybrid basin. The front and back walls are straight down (or at an angle, but still straight), but from side to side, the walls slope down into a rounded bottom.
Aside from the aesthetic style, different sink shapes also offer advantages in terms of size, so it’s something to consider if you want more room within your sink.
Rectangular shaped sinks offer more sink volume than rounded sinks of the same width. Flat bottom sinks offer more volume than rounded bottoms with the exact same counter space, especially if the walls are completely vertical.
On the other hand, more modern shapes aren’t without their disadvantages. Angles within the sink can have a tendency to accumulate dirt, so they can sometimes be a bit tricky to keep clean.
In addition, many flat bottom sinks have issues with draining completely.
Those are a few reasons to keep shape in mind when selecting an undermount bathroom sink. Which brings us to our next section…
What Do You Look For In The Best Undermount Bathroom Sink?
First is the material. The material you choose makes a big difference for the durability of the sink as well as on your bathroom decor.
Pure white vitreous ceramic and porcelain are by far the most common materials for bathroom sinks. However, sinks made from other materials, such as fireclay, stainless steel, or copper sinks, are also available.
There are other functionality considerations to consider as well. For example, what are the sink’s exterior and interior dimensions?
The exterior dimensions help you determine if the sink will work with your counter and under-cabinet space. In terms of counter space, that includes not just if the sink will fit in the first place, but if it will look overly large or small in the space and how much counter space will be left available for other needs.
The interior dimensions will give you an idea of the amount of usable space within the sink itself. Most people don’t need an especially large bathroom sink, but more space can be handy, such as for cleaning or soaking things.
Finally, virtually all bathroom sinks, including under-mount bathroom sinks, use the same standard drain diameter, 1.75 inches, but it’s always a good idea to double-check what size of drain opening you need and what size the sink’s drain hole is just in case.
Similarly, virtually all bathroom sinks will also have an overflow drain to prevent the sink from overfilling, but again, it’s always a good idea to double-check what the sink you’re looking at does before you buy. The absence of at least one overflow hole can result in a big mess at best or severe water damage at worst.
Best Undermount Bathroom Sinks Reviewed
Now that you know more, let’s talk about some excellent bathroom sinks.
Our overall top pick is the Kraus Elavo Rectangular Undermount 23” Ceramic Bathroom Sink.
It’s also the largest sink on this list with the interior of the basin measuring 21 x 14.38 x 6.13 inches, giving you plenty of room. The three overflow holes ensure that this large sink won’t overfill.
This rectangle ceramic sink is scratch-resistant and stain-resistant, so it should continue to look great for years to come. It also comes with a limited lifetime warranty. The smooth, glossy finish is easy to clean.
Our next pick is the Nantucket Sinks Rectangle Ceramic Undermount Bathroom Vanity Sink, a great sink for those shopping on a budget.
This is another vitreous china sink with a rectangular basin. In fact, the shape is very similar to that of the Kraus Elavo, with straight front and rear walls and a curve from one side to the other.
However, it’s a good bit smaller than the Elavo, measuring 16 x 10.875 x 5.875 inches, which accounts for the price difference.
Bowl depth is compliant with the American Disabilities Act (ADA)
Enamel glaze helps with durability and ease of cleaning
Some buyers have reported that the template provided isn’t necessarily accurate. You may want to wait until you have the sink in your possession to use as a guide before making a cutout in your countertop.
3. Kohler K-23350 Archer Undermount Bathroom Sink (Best High End)
If you are looking for a modern undermount bathroom sink, the Kohler Archer Undermount Bathroom Sink is worth spending a bit of extra money for.
But beyond the appearance and quality vitreous china, this flat bottom, rectangle undermount sink has another huge advantage. You can easily mix and match it with other Kohler Archer products, including bathtubs, shower bases, a toilet, and a medicine cabinet, to make finishing your bathroom decor totally painless.
The sink, tubs, shower bases, and toilet are all available in the same six colors, making it easy to coordinate them in the perfect color for your bathroom.
Can mix and match with other products in the Kohler Archer bathroom line
4. Decolav Callensia Rectangular Vitreous China Undermount Lavatory Sink
Another affordable option is the Decolav Callensia Rectangular Vitreous China Undermount Lavatory Sink.
It’s yet another vitreous china sink with a similar shape to our top and budget picks. It’s slightly larger than the one from Nantucket Sinks, though, with a bowl that measures 17.5 x 11.5 x 6.38 inches.
It’s actually a little bit cheaper than our budget pick as well, but some buyers reported quality control issues. This prevented us from making the Decolav Callensia our top budget pick.
Reports of excellent customer service when issues did occur stopped us from knocking this sink out of the top five entirely.
Bowl depth is compliant with the American Disabilities Act (ADA)
The attractive, high gloss ceramic finish is easy to clean
Excellent customer service
Only available in white
Some buyers report poor quality control, particularly in regards to the drain size and shape
Choosing the perfect undermount bathroom sink for your home can be difficult, but hopefully, this guide has made it easier for you. By now, you should know everything you need to make just the right choice.
And since each of these sinks is an excellent, high-quality option, you shouldn’t have to spend a bunch of time browsing options either. Just keep in mind the factors we discussed, like size, shape, material, and style, as well as your budget, and choosing the right sink should be easy.