Did temperature changes cause my quartzite island top to crack?
Estimated Reading Time: 2 MinutesQ. We had a quartzite counter island installed. The top was set flat on the cabinet, and there has been no movement. A crack appeared about one month after the installation. The crack goes opposite of the natural veining in the stone. There is a warming drawer below the top. We had a party and left the warming drawer open for about an hour or more. The top was warm and we cleaned the top with cool water. Could this have caused the quartzite to crack, going from hot to cool? Thanks for your input.
A. It is a frustrating situation to see a crack appear in a natural stone countertop. Unfortunately, this type of damage is surprisingly common. You're correct in assuming that the crack is most likely caused by a sudden change in temperature, i.e., thermal shock.
Quartzite expands when heated and contracts when cooled. When the warming drawer was left open, the stone above it became quite warm, but the rest of the countertop stayed much cooler. Then, the cool water caused the molecules in the hot area to contract faster than the surrounding material. Since stone is rigid, that such uneven movement creates internal stress, causing cracks to form.
A professional stone restoration contractor may be able to fill the crack with color-matched epoxy or resin and then hone and polish to matching the surrounding finish. In many cases, such repairs make the damage much less obvious. It’s worth calling a pro to assess it. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO. Larger or deeper cracks may require replacement of a section of slab. In that case, you'll need to call a stone fabricator, perhaps the fabricator who installed the countertop. Ideally, they will have slab remnants available from the same slab or a very similar slab.
Quartzite is durable and beautiful, but even tough natural stone can crack under rapid temperature swings. To prevent future damage, allow the stone to cool naturally before cleaning.
ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]