How to Fix a Cracked Quartz Countertop

Quartz countertops are durable and long-lasting, but cracks can still occur over time. Fixing a cracked quartz countertop is possible with the right materials and techniques. Here is a step-by-step guide on how to repair cracked quartz countertops.

Assessing the Damage

The first step is to assess the extent of the damage. Small hairline cracks may be repairable, but large cracks or chips will likely require professional help.

  • Examine the crack closely. Are the edges sharp and clean or jagged? Clean breaks can often be repaired more easily.
  • Determine if the crack goes all the way through the slab. Surface cracks are simpler to fix than ones that penetrate deep into the countertop.
  • Look to see if any pieces have chipped off near the crack. Missing pieces make DIY repairs more challenging.
  • Consider if the crack affects the structural integrity or stability of the countertop. Severe cracks may mean the quartz needs replacing.

Cleaning and Prepping the Area

Once you’ve assessed the damage, clean and prepare the repair area:

  • Clean the crack and surrounding countertop with isopropyl alcohol to remove any dirt, oil or debris.
  • Use painter’s tape to mask off the area around the crack. This keeps the workspace clean and avoids getting epoxy on adjacent surfaces.
  • Bevel the edges of the crack using a diamond grinding wheel or rotary tool. This helps the filler adhere and avoids weak spots.
  • Vacuum up any quartz dust or particles. The area must be completely clean for the repair epoxy to bond properly.

Mixing the Epoxy Filler

For the best crack repairs, use a specialized quartz countertop epoxy:

  • Choose a two-part epoxy formula designed for stone surfaces. The epoxy must cure rock-hard to stand up to daily use.
  • Mix the epoxy resin and hardener according to the manufacturer’s instructions. Only mix as much as you can use within the working time.
  • Add the provided color tint to closely match the hue of your quartz slab. Stir until the color is evenly dispersed.
  • Work quickly but carefully to avoid messy spills. The epoxy can permanently stain surfaces.

Filling the Crack

Once your epoxy filler is prepped, work it into the damaged area:

  • Use a putty knife to fill the crack, pressing the epoxy deep into the void. Apply extra epoxy above the surface to allow for shrinkage as it cures.
  • For best results, fill the crack in layers, allowing each layer to partially cure before adding the next. This prevents sagging and an uneven surface.
  • After the final layer, use plastic wrap or tape to compress the epoxy into the crack. This helps force out any air bubbles.
  • Remove any excess squeezed out epoxy with a putty knife before it fully cures. It can be much harder to sand off later.

Curing and Sanding

After applying the epoxy, allow time for it to fully cure:

  • Cure times vary, but most quartz epoxies take 24-48 hours to fully harden. Avoid disturbing or cleaning the area during this time.
  • Once cured, use 220-400 grit sandpaper to smooth and blend the repair. Be careful not to scratch the surrounding countertop.
  • Sand until the epoxy is perfectly flush with the quartz surface. Unevenness will be noticeable over time with use.
  • Finish by cleaning off all sanding dust and polishing with a soft cloth. The repair should now seamlessly match the slab.

Preventing Future Cracks

To help avoid more cracks in your quartz countertops:

  • Use cutting boards and hot pads to protect the surface from knives, pots, and pans. Direct impacts can damage quartz.
  • Clean spills quickly to prevent liquids from seeping into cracks and expansions joints.
  • Avoid exposing the countertops to very high temperatures. Rapid heating and cooling can cause thermal shock.
  • Re-seal quartz every 1-2 years with specialty sealants to prevent staining and damage in pits and cracks.
  • Get cracks professionally assessed. Severe or structural damage may require quartz replacement if a DIY fix won’t restore integrity.

When to Call a Professional

For some cracks, professional help may be needed:

  • Cracks wider than 1/16″ or deeper than 1/4″ often require fabricated quartz repair.
  • Chips and missing pieces can be difficult to match with epoxy. A pro can cut and fit replacements.
  • If the crack affects the structure or stability of the countertop, replacement may be needed.
  • Repairs needed in poorly accessible areas like backsplashes or seams present challenges for DIY.
  • Badly damaged or extensively cracked quartz is often best replaced entirely. Professionals can template and install a new slab.


Fixing cracked quartz countertops takes patience and the right materials, but is often possible for small surface cracks. Make sure to properly assess the damage, prep the area, mix quality epoxy, and allow full curing and sanding time. With care, most cracked quartz countertops can be attractively and seamlessly repaired. Calling in a professional is advisable if the cracking is extensive or affects the integrity of the countertop. With prompt attention and care, most cracked quartz countertops can be given new life with DIY repairs.