How to Repair Crack in Engineered Quartz Countertop

Engineered quartz countertops are popular in many homes due to their durability, aesthetics, and low maintenance. However, like any other countertop material, they can develop cracks over time. The good news is that minor cracks in engineered quartz can often be repaired fairly easily. Here is a step-by-step guide on how to repair a crack in an engineered quartz countertop.

Assessing the Crack

The first step is to thoroughly examine the crack to determine the extent of the damage.

  • Check if the crack is superficial or if it goes all the way through the thickness of the countertop. Through-cracks are more problematic and difficult to repair.
  • See if the crack has caused any loose pieces or fragments to come off the countertop. This will need fixing before repairing the crack itself.
  • Determine if the crack extends across the entire width of the countertop or just a small section. Cracks covering a large area can mean the substrate or support underneath is compromised.
  • Try to figure out what caused the crack in the first place. Cracks from accidental impact can often be repaired, while cracks from excessive heat or shifted supports may need countertop replacement.

Cleaning the Crack

Once you’ve assessed the severity of the crack, clean it thoroughly before attempting any repairs.

  • Use a vacuum cleaner attachment to remove any loose debris or fragments from the crack.
  • Mix a cleaning solution of mild soap and warm water. Use a soft cloth to gently clean the entire crack area and remove any dirt, grime, or residues.
  • Allow the crack to fully dry after cleaning before moving on to the next steps.

Preparing the Repair Area

Proper preparation is vital for achieving a durable, lasting repair.

  • Use painter’s tape to mask off the area surrounding the crack repair. This keeps the repair materials only on the crack and prevents mess.
  • If the crack has caused loose pieces or fragments, use cyanoacrylate glue to securely reattach them to the countertop. Let the glue cure completely.
  • Sand down the edges of the crack with 120-220 grit sandpaper to roughen up the surface. This helps the repair material adhere better.
  • Vacuum and wipe down the area one more time to remove all dust and debris after sanding.

Filling the Crack

Now the actual crack repair can be done using the appropriate filler material.

  • For narrow hairline cracks, use a quartz countertop repair kit containing colored epoxy filler. Follow kit directions to mix and apply the epoxy.
  • For wider cracks, use an auto body filler designed for stone repairs. Catalyze and apply it according to product specifications.
  • For deep through-cracks, fill from underneath too using epoxy or filler before applying to the top. This prevents sagging.
  • Build up the filler material slightly higher than the countertop surface. Once cured, you can sand it down flush.
  • Allow sufficient curing time based on the product directions before sanding or finishing.

Blending and Finishing the Repair

The last steps involve blending the repair so it aesthetically matches the rest of the countertop.

  • Once fully cured, use 120-220 grit sandpaper to smooth and level the filler material flush with the surrounding surface.
  • Further blend and polish the repair by hand-sanding using progressively finer 400, 600, 800, and 1000 grit abrasive pads.
  • Use a quartz countertop repair kit finishing polish to buff out any haze and blend the sheen. Clean off all residue.
  • For cracks near the sink, seal the repair with a waterproof silicone sealant to prevent water damage. Allow sealant to cure before use.
  • Remove painter’s tape and any remaining debris. The crack repair should now be durable, blended, and ready for use!

Tips for Preventing Cracks

To help avoid cracking your engineered quartz countertops in the future:

  • Always use cutting boards and trivets under hot pots and pans to prevent thermal shock.
  • Avoid sitting or placing excess weight on countertops which can cause stress cracks.
  • Address any unevenness in base cabinets that may put undue stress on countertops.
  • Clean spills promptly to prevent liquids from seeping into seams and cracks.
  • Have countertops professionally installed and maintain proper support underneath.

FAQs About Repairing Engineered Quartz Cracks

Can all cracks in engineered quartz be repaired?

Minor cracks and chips can often be repaired cosmetically. However, deep through-cracks, cracks from unsupported overhangs, or cracks covering large areas may require a countertop replacement.

What household items can be used to repair a small crack?

Clear nail polish or super glue can temporarily fill very fine cracks. For best results, use specialized quartz epoxy repair kits. Avoid household putty or wood fillers.

Should the entire countertop be resealed after a crack repair?

Resealing is not necessary unless the repair is near the sink or frequently wet areas. Use a targeted sealant only on the repaired section.

Can cracks reappear after repairing them once?

If the underlying cause of the original crack persists, such as inadequate support or excessive heat exposure, cracks can reoccur near the repaired area. Address the root cause to prevent more cracking.

How long does the repair last?

When done properly with the right materials and preparation, the repaired crack can last several years just like the original countertop. Follow all product specifications for most durable results.

What’s the easiest crack repair method for quartz countertops?

The simplest approach is using a colored epoxy repair kit specifically designed for quartz countertops. It fills hairline cracks with minimal preparation needed. Results won’t be seamless but can temporarily mask cracks.


Minor cracks and chips are fairly common in quartz countertops but don’t necessarily require full replacement. Often they can be repaired cosmetically using specialized filler and epoxy products. The key is proper cleaning, preparation, technique, and blending to achieve an inconspicuous fix that lasts. Address any underlying issues causing the cracks as well to prevent future damage. With some patience and effort, engineered quartz cracks can typically be repaired successfully. Just be sure to use recommended methods and materials for the most durable and seamless outcome.