How to Cut Installed Quartz Countertop

Installing a beautiful quartz countertop can greatly enhance the look and feel of your kitchen or bathroom. However, sometimes you may need to cut or modify the countertop after it has already been installed. Cutting a quartz countertop is not impossible, but it does require some special tools and techniques to avoid damage. Follow this step-by-step guide to properly cut your installed quartz countertop.

Gather the Right Tools

Cutting quartz requires a diamond-tipped blade designed specifically for this material. A standard wood or metal blade will chip and fracture the quartz. Here are the tools you’ll need:

  • Diamond-tipped quartz cutting circular saw blade
  • Circular saw with adjustable blade depth
  • Face mask and ear protection – quartz cutting generates lots of dust
  • Goggles or safety glasses
  • Marking pen
  • Straight edge
  • Vacuum with HEPA filter

Protect the Surface

Before making any cuts, carefully protect the surrounding countertop surface. Apply painter’s tape along the cut line to prevent the saw from scratching or damaging the quartz surface. You can also use duct tape. Cover nearby walls and cabinets with plastic sheeting to protect from flying debris and dust.

Mark and Score the Cut Line

Use a straight edge and marking pen to draw your cut line. Mark the line on the protective tape, not directly on the quartz. Make sure your line is perfectly straight. Lightly score the cut line with a utility knife – don’t cut deep, just mark the surface. This helps guide the saw.

Cut from Above

To avoid chipping, you must cut from above the countertop, not underneath. Remove any doors or obstructions that may block you from cutting vertically down onto the quartz surface. Adjust the blade depth so it will cut through the quartz but not into the cabinet below.

Make the Cut

Wearing goggles, mask, and ear protection, carefully line up the saw blade on the cut line before turning it on. Cut slowly and steadily straight down through the quartz. Let the blade do the work. Apply firm, even pressure, but don’t force the saw.

Clean Up

Turn off the saw and allow the dust to settle before removing plastic sheeting. Carefully detach painter’s tape from the countertop surface after cutting. Wipe away debris and vacuum thoroughly – quartz cutting dust can scratch the surface.

Smooth and Finish the Edges

Examine the cut edges for any rough areas and gently smooth them with 150-grit sandpaper. Finish the edges by applying quartz polish and sealing paste to prevent moisture damage. Allow sealant to cure overnight.

By following these safe quartz cutting techniques, you can achieve smooth, professional cuts in your installed countertop. Take it slow and don’t force the saw blade. With the right tools and preparation, cutting quartz yourself can save considerable time and money.

Frequently Asked Questions About Cutting Installed Quartz Countertops

Can I cut a quartz countertop after it is installed?

Yes, it is possible to cut a quartz countertop after installation. However, it requires special diamond-tipped blades and careful techniques to avoid cracking or chipping the quartz. With patience and the right tools, installed quartz can be modified.

What kind of saw do I need to cut quartz?

You will need a circular saw with a diamond-tipped blade specifically designed for cutting natural stone and quartz. Standard wood or metal blades will damage quartz. The diamond blades cleanly cut through the quartz without fracturing it.

Should I cut quartz from above or below?

Always cut quartz from above the surface, not underneath. Cutting upside-down can lead to chipping and cracking as the blade exits the material. Cutting vertically down provides the cleanest cut.

Can I cut all the way through a quartz countertop?

It is possible to cut completely through the slab, but consider whether this will impact the countertop’s structural support. Leaving at least an inch of quartz surface may be best to maintain stability. Consult an installer.

How can I prevent cracking when cutting quartz?

Work slowly with a sharp blade, scoring the cut line before sawing through the material. Don’t force or twist the saw, and always cut from above. Use painter’s tape along the cut line, and have someone help support the cutout area.

How do I get clean edges after cutting installed quartz?

Carefully sand any rough edges with 150-grit sandpaper. Finish the cut edges using a quartz polish and sealant made specifically for the material to prevent moisture damage.


Cutting installed quartz countertops takes precision, patience, and the proper tools. But with the right diamond-tipped blade, preparation, and techniques, it can be done safely without damaging the surrounding surface. Always remember to cut from above, go slowly, and smooth the cut edges. With some care, cutting quartz yourself can help save on installation costs.