How to Cut a Sink Hole in a Quartz Countertop

Cutting a sink hole in a quartz countertop allows you to install an undermount sink for a seamless look. Quartz is an engineered stone that requires special tools and techniques to cut accurately. With the right preparation and patience, you can achieve a clean sink cutout in your quartz countertop.

Necessary Tools and Materials

Cutting quartz requires diamond-tipped blades designed specifically for this material. You’ll need:

  • Diamond-tipped quartz cutting blade for an angle grinder or circular saw
  • Angle grinder or circular saw with adjustable speeds
  • Straight edge guide or carpenter’s square
  • Dust mask and eye protection
  • Earmuffs or other hearing protection
  • Marking pens and tape measure
  • Silicone caulk and surface cleaner

Preparing the Work Area

When cutting quartz, safety is paramount. The cutting blade produces fine stone dust that can irritate eyes and lungs. Follow these tips for a safe workspace:

  • Work in a well-ventilated area and use a dust collection system if possible
  • Wear a NIOSH-approved respirator mask, safety goggles, ear protection, and gloves
  • Cover nearby surfaces with plastic sheeting and tape to contain dust
  • Keep children and pets away from the workspace

Ensure you have adequate lighting and space to maneuver the quartz slab. Allow room for the saw to overhang the edge of your work surface.

Mapping Out the Sink Cutout

Map out the exact position and dimensions of the sink cutout before making any cuts:

  • Set the sink upside down on the countertop and trace the outline with a marker.
  • Measure the sink dimensions and mark the cut lines, allowing for any overhang into the sink basin.
  • Mark the depth of the sink rim or apron. account for this when marking the cutout.
  • Use a carpenter’s square or straightedge to mark straight cut lines.
  • Apply painter’s tape along the cut lines to prevent chip-out.

Double check all measurements before cutting to avoid expensive quartz mistakes!

Making the Straight Cuts

With your cut lines mapped out, you’re ready to start cutting:

  • Clamp a straightedge guide securely along the cut line.
  • Adjust the angle grinder or circular saw to the appropriate depth. Cut just deep enough to go through the quartz slab.
  • Make multiple gradual passes along the cut line, allowing the diamond blade to do the work. Don’t force the saw.
  • Cut very slowly to avoid overheating the quartz. Speed up quartz breakdown.
  • Stop frequently to spritz the blade with water to prevent overheating.
  • Make smooth, consistent pressure along the straightedge to ensure a straight cut.
  • Repeat for the remaining straight cuts.
  • Clean off marking lines with surface cleaner.

Cutting Interior Corners

For the interior 90-degree corners of the sink cutout:

  • Mark the interior corner cuts at precise 45 degree angles.
  • Carefully notch out the corner cuts with the angle grinder. Take it slowly.
  • Smooth and flatten the corner notches with a diamond sanding/grinding pad.
  • Test fit the sink and continue smoothing until the sink fits flush.
  • Clean away all dust and debris before dry fitting the sink.

Finishing Touches

Once the sink cutout is complete, make sure the installation is watertight:

  • Dry fit the sink and check for any gaps. Use the grinding pad to refine as needed.
  • Clean the cutout edges and sink bottom with denatured alcohol.
  • Apply a continuous bead of silicone caulk along the top edge of the cutout.
  • Carefully set the sink in place and press down firmly to adhere.
  • Allow the caulk to fully cure before using the sink (usually 24-48 hours).

With patience and the proper tools, you can achieve a flawless sink installation in your quartz countertop. Always take safety precautions when cutting quartz to avoid harming yourself or damaging the material.

Frequently Asked Questions

What are some tips for getting clean cuts in quartz?

  • Use new, sharp diamond-tipped blades specifically for quartz
  • Work slowly and don’t force the saw to avoid chip-out
  • Keep blades cool with water to prevent overheating
  • Make multiple light passes instead of one deep cut
  • Clamp straightedge guides to get straight cuts

Can I cut quartz with a jigsaw?

You can cut quartz with a jigsaw using a good diamond-tipped blade. But jigsaws are more prone to wander and chip the quartz. A circular saw with a straightedge guide is best for straight, clean cuts.

What should I use to smooth the cut edges?

Use a diamond pad sander or grinder to carefully smooth and polish the cut edges of the sink hole. Take it slow to prevent chip-out. Smooth any notches or corners until the sink fits flush.

How do I get a clean backsplash cutout?

Use a quartz backsplash template or measure and mark the backsplash cutout area. Clamp a straightedge and make multiple shallow passes with the circular saw to get a clean cut. Take your time and keep the blade cooled.

Can any silicone caulk be used to install the sink?

Use a dab of high-quality silicone caulk designed for kitchen and bath application. Avoid general use silicone. Ensure the caulk says it can adhere to quartz and withstand sink vibrations.


Cutting a precise sink opening in a quartz countertop is a manageable DIY project with proper planning and tools. Always use specialized diamond blades, take safety precautions, work slowly, and smooth out any imperfect cuts. Patience and care will reward you with a seamless undermount sink installation that spruces up your whole kitchen.