Adding an undermount sink can transform a simple kitchen sink into one with a sleek, updated look. Under the countertop, it enables easy wipe-ups of crumbs and spills. Undermount sinks can greatly improve granite countertops. However, you must install it properly to be secure and work efficiently for many years.
In this guide, we’ll show you how to install an undermount sink to granite step by step. From getting the right tools to sealing the edges, we’ll cover everything you need to know.

Tools and Materials You Will Need
Before starting the installation of your granite undermount sink, it is best to gather the materials and tools to set you up for success. The right tools will make your work easier and secure your sink satisfactorily. Working with the correct supplies could set you up for success, luckily, whether it is a kitchen in Columbus, Ohio, or anywhere else.
Here is a checklist of the items you need:
- Silicone adhesive: This creates a strong bond between the sink and the granite countertop. It also helps seal the edges to prevent leaks. It is necessary to use a high-grade waterproof silicone adhesive for great results.
- Mounting clips: These clips hold the sink tightly in place. These provide additional support so that the sink will not loosen over time.
- Drill and drill bits: A drill is essential for attaching the mounting clips under the granite to the proper sink. Use only correct drill bits that work for granite surfaces.
- Clamps: Clamps are capable of holding the sink steady while adhesive is applied and while attaching mounting clips. Clamps keep the sink properly aligned, which is important for that smooth, professional-looking finish.
- Cleaning supplies: Before installing, clean all areas of the granite thoroughly. Dust, grease, or leftover debris will interfere with the bonding of the sink to the countertop.
The right tools are essential while attempting to learn how to attach an undermount sink to granite. Skipping or using the wrong equipment could leave the fittings loose and lead to leaks, as well as poor sink alignment.
So, check your tools again to make sure everything is available before you begin your project. This will serve the purpose of being a stepping stone for a smoother and more successful granite undermount sink installation!
Preparing the Granite Countertop
Before you begin installing your undermount sink, it’s important to properly prepare the granite countertop. If this is not done, then there will be problems experienced-from a weak bond or poor alignment, resulting in the sink leaking or being loose at some point in time. Prep work takes time, but it is worth it to keep your sink from dropping and making things easier.
Then here is what you have to do:
1. Clean the Granite Surface Thoroughly
Applying gentle granite cleaning liquid to disinfect against dust, grease, or debris. Hopefully, even the smallest amount could weaken the adhesive bond so that everything is squeaky clean before you install. The edges of the cut-out areas – where the sink is supposed to be placed – must be cleaned as well.
2. Check the Sink Cutout
Now, before placing the sink, check the dimensions of the sink cut-out in the granite countertop. Is the cut-out congruent with the size and shape of the undermount sink? If rough edges are there, try to file them down and smooth; alignment will give your installation an attractive pro touch.
Preparation of an undermount sink installation to granite countertops is the number one thing here. When you get your cleaning and prep work done on your material, you then set yourself up for a strong and secure installation, which is going to be further long-lasting. “It’s a little thing to keep you from having to go through some issues in the future and keep this thing looking clean.”

Positioning and Securing the Sink
With a clean countertop ready, positioning and securing the sink become the next tasks. This step is vital, as proper positioning will ensure that the sink fits properly and remains firmly anchored.
1. Aligning the Sink
With extreme care, the undermount sink is to be positioned beneath the granite cutout. Make sure the sink lines up with the edges of the opening. This requires completion slowly and deliberately, as even minor misalignments can cause problems sooner or later. Under mounted sink granite installation requires careful alignment for a perfect fit, so double-check to make sure everything is even.
2. Holding the Sink in Place
Once aligned, it is now necessary to keep the sink steady while working. Use clamps or temporary supports to secure the sink. This will avoid any shifting as the adhesive is applied. Clamps are most advantageous as they tighten the sink against the countertop for a secure bond.
3. Applying the Adhesive
Now, generously seal around the edges of the sink, where the granite meets, with silicone sealant. Silicone acts as glue, bonding the sink onto the countertop and sealing its edges to prevent leaks. Make sure your application is even so that it stands a strong, watertight seal.
Once the adhesive has been in place, clamp the sink for hours (or as instructed by the adhesive) for the sake of curing it properly. This is the most important step that will ensure that your sink is held in place.
If you properly align, secure with clamps, and apply a strong adhesive, this will guarantee a professional look and long-lasting installation.
Sealing and Finishing Touches
The final step in your granite undermount sink installation is sealing the edges to prevent leaks and give the sink a clean, finished look.
1. Sealing Sink.
Apply a smooth bead of silicone all around the edge of the sink where it meets the granite for it to become water-tight, sealed against one’s chances of leaking. Apply sealant with a good caulking gun, but take your time: steady movement and pressure will give the best results.
2. Finish for a Clean Appearance.
Smooth with a finger or caulk with a caulking tool after applying silicone will give you a very clean professional finish. In case you decide to smooth the silicone with any of your fingers, it may also help to soak it in soapy water to prevent the silicone from adhering to your skin.
3. Drying Time/Clean Up.
Allow the silicone to cure for the amount of time specified by the manufacturer-usually no less than 24 hours. Do not use the sink during this time as the adhesive will not properly set. When the excess silicone is dry, wipe gently with a damp cloth to keep edges clean.
You have now done everything possible to seal the undermounted sink to granite, and sealing is the last phase of finishing the job. If you do it well and allow proper time for it to set after sealing, your sink will never leak and be ready for use for many years!

Common Mistakes to Avoid
During the installation of undermount sinks to granite, there exist minor mistakes that create subsequent serious problems. These common errors help you in getting optimum results while holding your sink tightly attached for years to come.
1. Misalignment
One of the most common mistakes includes aligning the sink through-the-countertop cutout, for misalignment will generally form an uneven fit as well as cause leakage of water. Hence be sure to make a double check before it’s glued down.
2. Poor Sealing
This means either not doing this step or doing it in a hurry: there has to be a very even layer of silicone sealant, and it has to be smoothed to get a watertight seal.
3. Using Weak Adhesive
Wrong adhesives might result in developing a loose sink. One has to use strong, good-quality, moisture-proof silicone adhesive, which is meant primarily for granite surfaces.
Avoiding these issues while doing the granite undermount sink installation shall give you long-lasting results that have a professional look.
Maintenance Tips for Your Undermount Sink and Granite Countertop
After learning how to mount an undermount sink to granite, it is vital to keep the sink, or vanity sinks, countertop, in good shape. Proper care and maintenance will help the sink stay clean, durable, and good-looking for years to come.
1. Cleaning the Sink and the Granite Surface
At least once a day, wipe your undermount sink, vanity sinks, and granite countertop with a soft cloth and a mild non-abrasive cleanser. This will remove dirt, grease, and water spots without damaging the surface. Avoid using strong chemicals or abrasive pads that can scratch the granite.
While you’re at it, remember to scrub around the edges where the sink bonds with the countertop. That area can trap grime and moisture, which over time can lead to either mildew or stains. Cleaning with a little brush or an old toothbrush will help keep the edges clean and dry. If you pay attention and clean this area regularly, that will help to keep your sink and granite surface looking fresh and maintained.
2. Prevention of Stains and Scratches
Granite is strong, but it can still get scratched or stained if not properly maintained. For a scratch-free surface and durability to uphold your undermount sink granite installation, here are some useful tips:
- Always use cutting boards while chopping or slicing.
- Immediately wipe spills, especially acidic fluids like lemon juice, vinegar, or wine, that may stain the granite.
- Never place hot pots or pans on the countertop directly. Use trivets to prevent heat damage.
- Never use abrasive materials to clean the stone. Use soft clothes or sponges to protect the fine polish from scratching.
- Seal your granite once in a while for additional protection from soaking in liquids.
- Try not to put stress on the edges of the sink that may cause chips or cracks around the undermount sink.
Following these rules will protect your granite countertop while helping the beauty and utility of your undermounted sink granite last for years.

3. Maintaining the Silicone Seal
A silicone seal could loosen or become worn in time around the undermount and vanity sinks. Check the seal regularly and note any peeling or cracking. If necessary, pull off the old sealant and apply a fresh coat of silicone to keep the seal watertight.
These tips should help protect your sinks and granite countertop from damage. With proper care and maintenance after installing an undermount sink in granite, your sink remains fit to look great and work well for years!
Need help getting it just right? Connect with a professional retailer who will offer you both a high-end quality sink and expert installation. Keystone Granite provides these premium sinks in a variety of types, colors, styles, and configurations. Also, our specialist team will carry out the expert installation for you so that you can have ever wanted to build your dream bathroom or kitchen space without a hassle!
Conclusion
Installing an undermount sink on a granite countertop will elevate the kitchen or bathroom style; however, doing the whole procedure in the right manner is key. Follow all the necessary steps with the right tools to secure a long-lasting fit. Regular maintenance will include sink and granite cleaning to keep it scratch-free and checking the silicone seal, which will be the solution to taking care of everything.
Need premium undermount sinks coupled with expert installation services? Get in touch with Keystone Granite and discover the best collection of undermount sinks in Columbus OH, that comes with a complementary installation for an ideal bathroom remodel package.
FAQs
1. How do you secure an undermount sink to granite?
You secure an undermount sink to granite using epoxy adhesive, clips, and silicone caulk for added stability.
2. Can you install an undermount sink after granite is installed?
Yes, you can install an undermount sink after granite is installed, but it may require professional help for proper alignment and support.
3. What is the best adhesive for an undermount sink to granite?
The best adhesive for attaching an undermount sink to granite is a two-part epoxy combined with silicone caulk for sealing.
4. Can you install an undermount sink without clips?
Yes, it is possible, but using only adhesive without clips may reduce long-term durability and support.
5. What is needed to install an undermount sink?
You need epoxy adhesive, silicone caulk, mounting clips, a clamp or brace, and proper tools like a caulk gun and level.