How to Mount a Dishwasher to Quartz Countertop

Installing a dishwasher can seem like a daunting task, but with some preparation and the right tools, mounting one to a quartz countertop is very doable as a DIY project. Here is a comprehensive guide on how to safely and securely mount a dishwasher to quartz countertops.


Quartz countertops are popular in modern kitchens because of their durability, aesthetics, and ease of maintenance. When planning your new kitchen or doing a remodel, installing a dishwasher helps maximize efficiency and convenience.

Mounting a dishwasher directly to quartz does require some special considerations compared to other countertop materials like granite or laminate. Quartz is extremely hard and cannot be cut on site, so all openings for appliances need to be made prior to installation. Quartz also lacks the traditional plywood or wood substrate underlayer, so dishwashers cannot be screwed directly into the countertop.

With some preparation and the right mounting brackets and hardware, installing a dishwasher to quartz counters can be accomplished successfully as a DIY project. The key is using a specialty mounting system designed for quartz and securing it properly into the cabinetry.

Steps to Mount a Dishwasher to Quartz Countertops

1. Prepare the Dishwasher Opening

  • Check that the height of the dishwasher matches the opening in the quartz countertop. Standard counter height is 36 inches.
  • Confirm the width of the opening matches the dishwasher, which is typically 24 inches.
  • Make sure the underside of the counter overhang is at least 34 inches high to allow room for the dishwasher door to open.

2. Install the Mounting Brackets

  • Use a mounting system designed for quartz like the InSinkErator system. It uses an L-shaped bracket and long screws to anchor into cabinets.
  • Position one bracket on each side of the dishwasher opening, lined up about 2 inches from the front edge.
  • Drill pilot holes and securely attach the brackets using the provided screws. Make sure screws are long enough to anchor firmly into cabinet framing.

3. Attach the Dishwasher

  • Set the dishwasher into position in the opening. Make sure rubber feet sit flat against the floor.
  • Underneath each side of the counter, attach the L-brackets from the dishwasher to the mounting brackets already installed using short screws. Tighten all screws securely.
  • Open the door carefully and check that it clears the counter and doesn’t hit anything through its range of motion. Make any adjustments needed.

4. Seal Around the Edges

  • Use 100% silicone caulk to seal all edges between the countertop and sides of the dishwasher for an airtight, watertight seal.
  • Apply caulk along underside of counter around the 3 exposed sides of the dishwasher. Smooth the bead with a wet finger.
  • Let the caulk cure fully for at least 24 hours before running the dishwasher. The sealant prevents leaks.

Tips for Mounting a Dishwasher to Quartz

  • Always use the manufacturer’s recommended mounting system and hardware to safely install the dishwasher.
  • Make sure your brackets anchor firmly into solid wood cabinet framing, not just drywall.
  • Take care not to crack or chip the quartz during installation. Pad tools to prevent damage.
  • If needed, adjust feet on the dishwasher to make it level and stabilize it.
  • Run a test cycle and check for leaks after installing before regular use. Tighten brackets if needed.
  • Make sure electrical and water lines have enough slack for the dishwasher to move during installation.

FAQs About Mounting Dishwashers to Quartz

How do you secure a dishwasher to quartz countertops?

Use specialty L-brackets anchored firmly into the cabinetry framing on each side of the dishwasher. The brackets attach to the bottom of the dishwasher to support it.

What kind of screws should be used to mount a dishwasher to quartz?

Long wood screws, around 2.5 to 3 inches, allow the L-brackets to be secured firmly into cabinet framing behind the dishwasher.

Should you silicone around a dishwasher on quartz?

Yes, use 100% silicone caulk to seal around all sides between the dishwasher and countertop. This prevents leaks from water splashes.

What can you use instead of an L-bracket to mount a dishwasher?

If an L-bracket will not work, specialty T-brackets or four-point floating systems made for quartz can also provide secure mounting.

How do you attach a mounting bracket to quartz?

Brackets designed for quartz have extra long screws that anchor into the wood framing under the counter. Do not attempt to screw brackets directly into quartz.


Installing a dishwasher in quartz countertops is very doable with some preparation and using the proper mounting brackets and installation method. Carefully follow the manufacturer’s instructions for the mounting system. Allow plenty of time for caulking and checking for leaks before regular use of the dishwasher. With some patience and the right techniques, you can have your new dishwasher mounted securely to beautiful quartz counters.