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Engineered Quartz Countertop Core Drilling

Custom stone fabrication work in commercial buildings often comes down to a simple problem: the existing countertop doesn’t quite work with the equipment being installed. At 2 Park Ave in Midtown Manhattan, an engineered quartz countertop had a small hole, roughly 1 inch across, left from a previous installation. It wasn’t big enough to allow adequate airflow for an undercounter water filtration and refrigeration unit. The solution was to core-drill it out to 3 inches on-site, without pulling the slab.

Engineered quartz is a man-made composite material. It consists of around 90 to 93 percent ground natural quartz crystal bound together with polymer resins and pigments. That mix gives it a Mohs hardness rating around 7, making it one of the hardest countertop surfaces available. It’s harder than granite in many cases and far more resistant to scratches than marble. Its non-porous structure means it does not absorb liquids, bacteria, or staining agents, which is why it gets used in commercial kitchens, breakrooms, and office environments.

Enlarging an existing hole in engineered quartz is more controlled than drilling a fresh one, but it still requires precision. The material’s resin binder helps hold the aggregate together under cutting stress, which reduces the risk of chipping compared to more brittle stone types. Professionals center the new core bit over the existing opening using a guide template, use a diamond-tipped bit rated for composite stone, and use water to prevent heat buildup in the resin matrix. Feed pressure has to stay steady throughout. Too light and the bit skips. Too heavy and the edge fractures.

The wood subtop below the quartz also needed to be enlarged to the same diameter. That part gets drilled second, with a standard hole saw once the stone cut is confirmed clean. Keeping both layers aligned is important. Any offset puts lateral force on the quartz edge whenever the cable or equipment moves.

ABC Stone Inc. handles on-site drilling and hole modification for engineered quartz, granite, marble, and other stone surfaces across New York City and New Jersey. Jobs like this one, where the countertop stays in place and work happens in a live office, are a regular part of what we do.

Engineered quartz countertop with existing hole before core drilling