How to Install an Undermount Bathroom Sink to Granite Countertop


Undermount bathroom sink installed on a granite countertop comes with distinction and class. Granite countertops are prevalent in most bathrooms because of their ability to resist scratching and chipping. They are also moisture, stain, and heat-resistant.

Undermount sinks don’t have an aperture or lip to catch dirt. You don’t have to worry about anything getting trapped under the sink rim while wiping away dirt.

That’s why the combination of an undermount bathroom sink and a granite countertop makes it ideal for a bathroom.

Though the process is straightforward, you need to install the bathroom sink correctly for optimal results. You will need to fix the sink under the counter and secure it using sealants like silicone adhesive, epoxy, or mounting sink clips.

How to Install an Undermount Bathroom Sink to a Granite Countertop

Can you Put an Undermount Bathroom Sink on a Granite Countertop?

If the granite countertop is made from natural stone, then it is possible to mount an undermount bathroom sink on it.

However, if the granite countertop is laminate, then it may not be able to take the weight of an undermount bathroom sink.

In this case, you would have to go with a conventional bathroom sink or buy a separate vanity that can house an undermount bathroom sink.

How to Install an Undermount Bathroom Sink to Granite Countertop

Before carrying out an undermount bathroom sink installation, you need to collect several essential items required for the procedure.

You will require;

  • Large towel
  • Pencil
  • Undermount bathroom sink and its mounting hardware
  • Silicone sealant
  • A clean piece of cloth

Step 1: Measure the Sink Hole

Undermount bathroom sinks come in various sizes. You will need to measure the space to fix the sink before buying to get the right fit. Measure all the sides, length, and depth. Then record your findings in a secure place.

Step 2: Choose a Sink

After getting the undermount bathroom sink measurements, choose a suitable sink based on your countertop’s measurements.

When choosing the sink, consider whether it suits the granite countertop. Not all types of undermount sinks can combine well with a granite countertop. Also, consider the design.

Then, consider how you want the sink to appear when installed. Would you want part of it exposed, the granite countertop to extend beyond the sink walls or the countertop edges to par with the sink’s walls? It depends on your preference.

Most homeowners go for the undermount sink style with zero reveal because it looks classic and does not have space for germs, grease, or dirt to hide. Inspect the selected sink to ensure it’s in order and has the necessary mounting hardware.

Step 3: Position the Sink on the Granite Countertop

Now I’m going to fix it on the granite countertop in your bathroom. First, pick a large, soft, clean towel and spread it on a flat and secure surface like on the table or the bathroom’s floor.

Then place it upside down on the towel. The towel will protect the countertop from becoming soiled or damaged by anything. The underside of the granite countertop should be facing you.

Step 4: Place the Sink on the Granite Countertop

After resting the countertop safely on the towel, place the sink to sit in its position. It means that the sink’s surface should face downwards on the sinkhole.

Ensure you position the sink properly with the faucet hole and the bolt holes.

Step 5: Trace the Outside of the Sink on the Granite Countertop

Once you’ve placed your sink evenly and correctly, trace its outline on the granite countertop using a pencil. Then place it carefully in a secure place sitting upright.

Step 6: Apply Silicone Sealant around the Sink’s Rim

After installing the undermount sink, apply silicone sealant around its rim. 

Step 7: Fix the Sink on the Granite Countertop

When you finish applying a bead of silicone around the sink’s rim, place it carefully upside down on the countertop. Ensure it lies within the outline.

Step 8: Attach Wing Bolts and Sink Clips

After being content that the sink rests correctly on the granite countertop, pick the wing bolts and sink clips and place them in their respective places on the sink. Then tighten them snugly. 

Step 9: Pick and Place the Granite Countertop and the Attached Sink in its Place

After tightening the mounting hardware as required, pick the countertop and place it in its position.

If the sink attached is heavy, you can request someone to assist you in lifting it and securing it in its place carefully.

When you need to reposition the sink, you only need to loosen the wing bolts and adjust the sink. Then retighten the bolts.

Final Step: Remove Excess Silicone with a Damp Cloth

Take a damp, clean, and soft cloth and pipe them all out. You should allow the sink to rest for 24 hours before use to enable the silicone sealant to dry.

Once a day has passed after the above steps, the bathroom sink installation to granite countertop will be complete and successful.

Final Thoughts

Undermount sinks with a granite countertop come with many benefits that you can enjoy only when you regularly maintain the sink.

Read More: how to attach undermount sink to quartz.

Granite countertops combine excellently with an undermount sink. When installed in the bathroom, the space looks appealing. Because of their many benefits, homeowners have opted to install them in their bathrooms.

Lisa Burks

This is Lisa Burks, the Author. I provide free informative sink and faucet guides. I hope you love your time here.

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