How to Install an Undermount Sink to Quartz Countertop

Installing an undermount sink to a quartz countertop can seem daunting, but with the right tools and technique, it can be done smoothly. Here is a comprehensive guide on how to install an undermount sink to quartz countertop.


Undermount sinks create a seamless look by dropping into the countertop rather than sitting on top of it. This makes cleaning easy as crumbs and spills can be wiped directly into the sink. Quartz is an excellent countertop material choice as it is non-porous, stain-resistant and durable. When paired with an undermount sink, it makes for a high-end, modern look. However, proper installation is required to ensure the integrity and water-tightness of the joint.

Before You Begin

Before starting the installation, make sure you have all the necessary supplies:

  • Undermount sink designed for quartz countertops
  • Quartz countertop cut to fit the sink
  • Caulk/adhesive specifically for quartz countertops
  • Brackets, screws and hardware for attaching the sink
  • Silicone sealant and caulk gun
  • Drill and drill bits
  • Safety equipment – gloves, goggles, mask

Check the fit of the sink in the countertop cutout before permanently attaching it. There should be a very small, even reveal between the sink edge and cutout.

Installation Steps

Follow these steps for proper undermount sink installation to a quartz countertop:

Clean Surfaces

Clean the underside of the quartz countertop and the top flanges of the sink with denatured alcohol. This removes any dirt, grease or residue that could interfere with proper adhesion.

Apply Adhesive

Apply a zig-zag bead of adhesive specifically designed for quartz countertops along the top of the sink flange. Use enough to create a solid seal but be careful not to over do it.

Set Sink in Place

Carefully set the sink in place in the countertop cutout, pressing firmly to adhere the sink. Be sure the reveal between the sink and cutout is even on all sides.

Attach Mounting Brackets

From under the countertop, attach the provided metal mounting brackets at the front and back of the sink. Tighten the screws just until they are snug.

Allow Adhesive to Cure

Follow the adhesive manufacturer’s instructions for cure time. Typically this is 12-24 hours before further tightening the brackets or using the sink.

Further Tighten Brackets

After the full cure time, check the brackets and tighten the screws further if needed until the sink feels fully secure and supported.

Apply Sealant

Run a continuous bead of silicone sealant around the entire sink and countertop joint. Use a finger or smoothing tool to spread the sealant evenly and remove any excess.

Allow Sealant to Cure

Allow the sealant to fully cure overnight before using the sink. The silicone will become transparent when fully cured.

Tips for Success

  • Take your time when applying the adhesive to prevent leakage.
  • Be sure to use adhesives and sealants designed specifically for quartz.
  • The sink should be supported by mounting brackets, not just adhesive.
  • Allow proper cure times for adhesives and sealants.
  • A small reveal between the sink and cutout is ideal for a neat appearance.
  • Keep the quartz countertop edge flat – do not bevel it.


What type of caulk should be used with a quartz countertop?

Use a high-quality silicone caulk made specifically for quartz and solid surface countertops. Avoid acrylic latex caulks.

Can any undermount sink be used with quartz?

No, sinks meant for undermounting are specially designed with appropriate flanges and dimensions. Make sure to choose a sink marketed as an undermount for quartz or solid surface countertops.

Should anything be applied to the quartz before installing the sink?

No. Quartz does not require priming or preparation before attaching the sink. Simply ensure the surface is clean.

How long does the adhesive need to cure before using the sink?

It depends on the adhesive used, but typically 12-24 hours is needed for the initial cure time before applying weight or water pressure. Always follow the manufacturer’s instructions.

Can weight or strain be applied to the countertop during installation?

No. Once the sink is set in the adhesive, avoid putting any weight on the countertop surrounding the sink until the adhesive has fully cured.


Installing an undermount sink can transform the look of a quartz countertop. While the process requires attention to detail, having the right tools and following best practices will result in a successfully secured, water-tight installation that will last for many years. Be sure to use the recommended adhesives and sealants and allow proper cure times. With some patience and care, you can gain the streamlined, high-end look of an undermount sink paired beautifully with durable quartz.