How to Drill Undercounter Holes for a Dishwasher in Granite Countertops

When installing a dishwasher, use screws that attach the unit to the counter. The screws secure the dishwasher into place, preventing movement that occurs due to vibration. All dishwashers come equipped with a metal bracket and designated screw holes. When securing a dishwasher to masonry-type counters, use blue screws, which are fasteners designed to be used with rock materials such as granite. Blue screws are constructed of a harder material than regular screws, and are covered with blue paint, which performs like a lubricant when heated.

Step 1

Slide the dishwasher into the designated opening. Adjust the dishwasher, by leveling and plumbing it, to the desired position.

Step 2

Equip an electric drill with a masonry bit featuring the same diameter as the screw that will be used to secure the dishwasher. Use a regular drill, rather than a hammer drill, to prevent cracks and chips in the granite countertop.

Step 3

Hold the blue masonry screw up to the drill bit. The head of the screw should be located at the tip of the drill bit. Wrap tape around the drill bit so you know how deep you need to drill. This will prevent you from drilling too far or not enough into the granite.

Step 4

Slide the tip of the drill bit through the designated holes located at the top of the dishwasher. The bracket will prevent the drill bit from moving while you drill the holes.

Step 5

Hold the drill at a 90-degree angle and make a hole in the granite countertop. Start the drill slowly to allow the bit to make a rut so that it doesn't slip around.

Step 6

Insert the blue masonry screws into the drilled holes and tighten them with the appropriate size bit; refer to the screw packaging to determine the correct size to use.