How to Repair a Chip in Granite or Quartz Countertops

Sometimes. A chip under a quarter inch, on a flat area, with no crack running from it, is a fair home job with a two-part stone filler. From a quarter to three quarters of an inch, send photos to a fabricator first. Over three quarters of an inch, or at a sink or cooktop cutout, it belongs with a fabricator.

A chip is not always only a chip. The Natural Stone Institute says deeper scratches and nicks in natural stone should be repaired and repolished by a professional. If you cannot see the bottom of the chip, treat it as the professional case. That depth test is a judgment call.

New Granite & Marble in Hawthorne lists chips, cracks, stress marks, stains and open seams on its repair page. Which stones and damage it takes on is a question for the shop.

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Size, location and cracks decide it. Slabwise calls chips under a quarter inch solid do-it-yourself territory and sends anything over three quarters of an inch to a fabricator, though its summary says chips over a half inch usually need a professional. Dynamic Stone Tools puts the line at 25 millimeters, about an inch.

Hunker (a 2019 guide about granite only) says a crack that a dime or thin knife blade slips into needs repair because it can spread, and that hairline cracks blend into the stone. Slabwise adds a spread test: tape over the damage, mark its edge with a permanent marker, and check every few days. If it grows past the line, call a professional.

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Cambria says objects hitting edges, particularly at sinks or dishwashers, may cause chips, and that no stone is chip-proof. Caesarstone's fabrication guide lists an insufficient or incorrectly made radius on cutouts as a cause of cracks at sink and cooktop cutouts.

It asks for a minimum radius of 10 mm, about three eighths of an inch, on every cutout corner. For cutouts longer than 600 mm (24 inches) it recommends beams under the top where possible, and it asks for support under all seams. So a crack at a cutout with no impact behind it can point at how the top was made or supported. Raise that with the installer before you reach for adhesive.

Water is another cause. In a JLC Online repair of two cracked granite sink cutouts, a homeowner had hidden one crack with black caulk. The contractor found latex caulk at the sink flange and plain steel rods in the stone. Water got past, a rod rusted and expanded, and the stone cracked. He removed the rod, glued the granite back with epoxy and reset the sink. That was granite with embedded rods, so it says little about quartz.

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Clean it, mix a stone-rated two-part filler tinted to match, fill slightly high, let it cure fully, then scrape it level. Color matching takes several attempts. These steps follow Slabwise and Dynamic Stone Tools; your product's label overrides them.

• Wipe the chip with acetone on a lint-free cloth and let it dry at least five minutes. Do not let acetone pool.
• Mix to the label ratio for at least 60 seconds. Test the tint on white cardboard or a scrap of the same stone and let the dot cure; cured resin often looks different from wet.
• Fill so the filler sits just above the stone. Slabwise builds a deeper chip in two thin layers with a cure between.
• Cure times differ by product. Dynamic says polyester is typically 15 to 45 minutes. Slabwise says to leave a 30-minute epoxy at least 90 minutes and to double any label minimum before sanding.
• Scrape flush with a sharp razor blade at about 30 degrees to the surface.
• On quartz, Slabwise wet-sands at 400, then 800, then 1500 grit and buffs with a quartz-safe polish.

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Follow the product label, because the guides disagree. Granite Selection suggests super glue for light-colored quartz. Slabwise says not to use it as the primary filler on quartz because it can turn cloudy, shrink and not sand cleanly. Dynamic calls two-part polyester resin the industry standard for granite.

On dust, OSHA and NIOSH say workers using saws, grinders and high-speed polishers have some of the highest exposures to respirable crystalline silica in countertop work. Engineered stone can be up to 95 percent crystalline silica and granite up to 50 percent. The alert covers workers, so it gives no home limit. Skip power tools and ask a shop to grind.

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Usually a home fill does not void the rest of a warranty, but that chip will not be covered afterward. That is Slabwise's position, a vendor guide and not a stone maker's statement. Read your own. Slabwise also warns that repairing a defect you have claimed could close the claim, so call the maker first if a claim is open.

Cambria's warranty page describes a transferable full lifetime warranty and gives 1-866-CAMBRIA for claims. It lists no exclusions; it links a longer warranty document that was not opened for this article, and other brands' warranties were not opened either. Photograph the damage first, with a coin for scale.

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Ask for the contractor's State registration number. New Jersey's Contractors' Registration Act requires home improvement contractors to register with the Division of Consumer Affairs, and the number must be on the contract. Past a small-job threshold the contract must be in writing with the dates, the work and the total price.

The Division advises against paying for the whole job upfront or in cash, and says final payment can't be demanded before the work is finished. A signed contract can be canceled before midnight of the third business day after you get it.

• Are you registered with Consumer Affairs, and what is the number? Do you carry liability insurance, and can I have a copy of the policy?
• Can you show me a color match on my stone before you fill the chip?
• Will you look at why it chipped or cracked, such as support or the sink seal, not only fill it?
• Is the repair guaranteed in writing?
• Will this affect my stone maker's warranty, and have you dealt with that maker before?

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Photos and a few lines are enough to start. Ask whether the shop takes on repair for your stone, through the form or by phone. Send:

• A close photo with a coin for scale, and a wide photo showing the sink, cooktop and seams
• Stone name or brand and color, if you know them
• Who installed it and about when
• Any crack you can see or feel, and any earlier repair attempt

More on this site: granite countertops, quartz countertops and contact the shop.