How to Install An Undermount Kitchen Sink? Ultimate Guide

To install an undermount kitchen sink, first, you’ll have to remove the old sink by cutting the sealant and unscrewing the metal clips. Next, replace the faucet and scrap all the silicone. Now get a new sink, apply sealant and let it set. After that set a 2″ x 4″ bar clamp on the countertop and attach the bracket properly.

Seems quite difficult, right? I wouldn’t say it’s easy, but if you read this whole article, it should feel less hard for you. Because I’ve explained everything here in proper detail. So, continue reading.

What Is An Undermount Kitchen Sink?

An undermount kitchen sink is a type of kitchen sink that is attached to the underside of a kitchen counter. This sink is mounted from below and held tightly to the underside rim with any adhesive or heavy clip or bolts. Besides, extremely strong epoxy adhesives are used to secure the bolts and brackets of the sink. Undermount sinks are installed under the counter, unlike the sink, which is dropped into the pre-cut hole of the countertop.

Advantages of An Undermount Kitchen Sink

Let’s see what you’ll get from this amazing type of kitchen sink-

The undermount kitchen sink gets less dirty than the regular sink. The reason is, the undermount sink has a hidden double bowl option.
This type of sink is completely seamless as the edges of the sink are completely hidden.
Undermount sinks are quite stylish, sleek, and extremely gorgeous to look at!
These sinks are customizable with versatile materials like quartz, granite, and laminate.
This sink gives your countertop extra space rather than eating up more space.
Undermount sinks let you easily clean up as you can just wipe the food, any particles, or dirt directly into the sink!

How to Install An Undermount Kitchen Sink?

This is the main segment of the article. I’ve described all the steps in a very easy way dividing them into 2 parts. So, let’s get started-

Necessary Tools

Undermount Sink
Utility Knife
Silicone Caulk
Bar Clamp
Silicone Sealant
Mounting Hardware
Denatured Alcohol
2″ x 4″ Lumber

Removing The Old Sink

You’ve to start by removing the old sink if you already have one. Let’s see the process-

Step 1: Detach The Plumbing Fixtures

Remove any plumbing fixtures like garbage disposal and switch off the water line. Get a bucket to catch any water droplets and a rag to wipe out any excess water. Shut down the garbage disposal also and remove it aside.

Step 2: Remove The Old Sink

Most of the undermount sinks are attached with silicone sealant and metal clips. With the utility knife cut the sealant and unscrew the metal clips that are holding the sink with the countertop.

Step 3: Faucet Replacement

Now, if you want to replace your faucet, then it’s time to do that. Wear your protection goggles and mask while doing the faucet replacement task.

Step 4: Scrape The Silicone

Just use any razor or scraper, so you can carefully scrape down all the silicone left behind on the countertop. Be careful not to be harsh on the countertop.

Step 5: Cleanup Everything

You’ve completed 90% of your job. Now, just use denatured alcohol at the both top and bottom sides of your countertop to remove any residue of dirt. Now, it’s ready for the new undermount sink installation!

Installation of New Sink

Let’s work on the installation process now-

Step 1: Apply Silicone Sealant At The Sink Edges

Position your new sink under the below cutout of the cabinet. Use your silicone sealant and a layer of it along the edges of the sink.

Step 2: Let The Sink Set

In this step, take the help of two people. One will raise the sink on the countertop while the other person will monitor if it’s properly positioned in place.

Step 3: Set The Bar Clamp

Now, lay a 2″ x 4″ bar clamp on the countertop. To prevent any damage to the countertop, use two towels at the end of the clamps. Through the drain hole, run one of the ends of the bar clamp.

Besides, you may need to know if your Drain has been Leaking: How to Fix Kitchen Sink Drain Leak?

Step 4: Attach Another block

Get another 2″ x 4″ block and position that on the underside between the clamp and the sink. It’s done to avoid any damage to the underside of the sink.

Step 5: Attach The Brackets & Tighten The Clamp

Now connect the brackets with the mounting hardware. Then, tighten the clamp to set the sink tightly in place.

Step 6: Remove Any Residue Silicone

Take a damp towel or a rag to wipe out any residue silicone that spilled out into the sink while setting the sink inside.

Step 7: Rest It Until It Dries

Wait a minimum of 24 hours to let the silicone dry and set the sink set tightly. Plus, also don’t remove the wooden clamp before 24 hours.

Step 8: Reattach Any Plumbing Fixtures

Now, attach your faucet, turn on the water line, switch on your garbage disposal and reattach any plumbing fixtures you turned off. And your work will be done!

Besides, you may read: How to Mount A Butcher Block Countertop? 8 Step Guide!

How to Install Undermount Sink to Granite Countertop?

Granite is a sturdy and durable material that lasts very long and comes in various colors. It’s unique in style and family-friendly. Let’s see the installation process of the under-mount sink to the granite countertop-

Step 1: Measure Your Sink

First, measure your sink opening on the granite countertop. Mostly the measurement is 33″ x 22″ from the outside edges. While selecting your new sink, remember the measurement.

Step 2: Choose Your Sink Revealing Style

There Are 3 styles you can choose from. Revealing style means how much the sink edge will be visible after the installation. The 3 types are-

Positive Reveal: Exposes some parts of the sink.
Zero Reveal: Countertop edge openings will be flushed with the sink walls.
Negative Reveal: The countertop goes into the sink walls.

Most of the time Zero Reveal style is chosen for a home or any structure as it looks quite professional and minimalistic. Plus, it leaves no place for dirt and germs. Whereas, the Negative style is quite bothersome to clean.

Step 3: Set The Sink In the Proper Place

Position the sink properly along the edges of the countertop. When the sink is placed, mark those positions where you need to drill holes. Now, take the sink out and drill holes in those spots.

Step 4: Apply Silicone Sealant

On the sink lip, apply a thin layer of silicone sealant. Then, place the sink from underneath and adjust it to the granite countertop. While positioning the sink, make sure to clean up the caulking. It’ll look more sleek and professional then.

Step 5: Screw The Nuts & Brackets

On the screw heads attach all the brackets and screws tightly.

Step 6: Tighten The Sink

Now, ensure the tightness of the sink, and press on the sink with any wood or your hand on the edges to get out any trapped air.

Step 7: Cleanup Any Residue

Lastly, take a damp rag and clean out any oozed sealant or any dirt. Then, with the alcohol, wipe out any residue or dirt. Leave for a while to dry it out.

Or check this video!

How to Install Undermount Sink To Quartz Countertop?

Here comes the installation process-

Step 1: Measure The Outline Of the Sink

First, turn the quartz countertop upside down and position it on any flat surface. Now, position the undermount sink on the top of the sinkhole and check if it’s properly aligned. With a pencil outline the traces and then remove the sink.

Step 2: Clean The Edges

Take your alcohol and wipe the edges around the sinkhole, so it can be well-attached with glue.

Step 3: Use The Sink Clips

In plumbing stores, you’ll get 10 undermount sink clips in a package. Take 6 clips and position 4 clips at the outer 4 edges and 2 at the center.

Step 4: Epoxy Time

Mix the epoxy in equal quantities and pour it into the holes of the clips. To ensure the clips are firmly positioned, squeeze the clips into the epoxy.

Step 5: Wait For A While

Don’t immediately rush to attach the nuts and brackets. Wait for a while to let the epoxy set.

Step 6: Apply Silicone Caulk

On the rim of the sink where the sink exactly sits, apply silicone caulk in a very thin layer.

Step 7: Set The Sink In

Now, turn the sink upside down and install the sink on the spots you’ve marked beforehand. Press the sink firmly with your hand to ensure that the silicone has spread properly.

Step 8: Attach The Nuts & Brackets

At this point, the epoxy should have been dried and the clips should be hard enough to touch. Now, connect the nuts and brackets to hold and secure the sink.

Step 9: Final Cleanup

Let the sink sit on the countertop for 1-2 hours before handling it again. Plus, with the alcohol, wipe out any residues or dirt!

How to Install an Undermount sink to Laminate Countertop?

The process of installing an undermount sink on a Laminate countertop is similar to the process mentioned in Granite Countertop. So, check the process above again for installing an undermount sink on a laminate countertop.

How to Replace Undermount Sink Without Removing Countertop?

Now I’ve come up with the undermount kitchen sink replacement guide. You’ll have to start removing the part by supporting the sink. As the sinks are made of heavy materials, they can fall on the ground and cause damage. So, you’ve to follow some steps.

Place a 2″ x 4″ wooden clamp on the top of the sink and make sure to get it parallel to the countertop.
Get a wire (12 gauge) and twist it 7/8 times around the clamp and down through the drain. There should be a 12″ wire hanging down the sink.
Now, wrap the wire around a wooden dowel of 6/8″ in length. Wrap it until the wire firmly attaches to the base of the sink.
Once you get the sink free, lower the sink slowly by untwisting the wire.

Removing The Sink

First, disconnect all the plumbing fixtures like the faucet, garbage disposal, and water line.
Now, with proper support, remove the old sink carefully.
Then, Scarpe out all the silicone or epoxy glue.
Lastly, with the alcohol, wipe out any residue dirt and wait until it dries.

How Much Will It Cost to Install An Undermount Kitchen Sink?

The Installation process, along with the cost of a new sink in the bathroom or kitchen, goes from the $200-$1,500 range. Nowadays, these sinks are quite popular for the reasons of- easy cleaning way, sleek look, and convenience to use.

Final Verdict

So, I am done explaining the topic – how to install an undermount kitchen sink?

To be honest, installing an undermount kitchen sink is quite tough. So, you must seek help from any professional service if you don’t feel confident.

Any plumbing service will do this work, but all you’ve to do is to choose the style of your undermount sink. After installing the sink, you must maintain the sink properly. The sink needs to be well-supported as they tend to be quite heavier than the regular sink. Though I’ve broken down every step of installing the undermount kitchen sink, if you feel insecure, it’s better to get help from the experts. Best of luck!

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