How to Install a Dishwasher with Quartz Countertop

Installing a dishwasher with a quartz countertop requires careful planning and execution to avoid damaging the countertop. Quartz is an engineered stone that is durable but can be prone to chipping if proper precautions are not taken. Follow these steps for a smooth installation.

Choose the Right Dishwasher

When selecting a dishwasher for a quartz countertop, opt for an 18″ or larger built-in model. The larger size allows the dishwasher to sit under the counter flush with the cabinetry. Ensure the dishwasher you choose is specifically made for undercounter installation and has an adjustable height mechanism.

Avoid portable dishwashers that sit on top of the counter, as their weight can cause stress points that lead to cracking. Undercounter dishwashers are designed to integrate seamlessly into the cabinetry and bear weight properly on the subfloor.

Prepare the Dishwasher Alcove

The dishwasher alcove is the space under the counter where the appliance will be located. This area needs to be prepared prior to installation:

  • Remove existing flooring down to the subfloor. Dishwashers require a smooth, level surface to sit on.
  • Confirm the height from the subfloor to underside of the countertop is between 32.5” – 34.5” for proper fit.
  • Install blocking between cabinet sides if needed to secure the dishwasher.

Adjust the Dishwasher Height

Dishwashers have adjustable front legs that alter the height of the appliance. For a quartz countertop installation:

  • Set the legs to the lowest possible height.
  • Slide the dishwasher into the alcove to confirm it fits under the counter.
  • Adjust the legs up slightly until the top of the dishwasher just makes contact with the countertop. You want a snug fit with no gap between the counter and appliance top.

Attach the Mounting Bracket

Undercounter dishwashers come with a metal mounting bracket that gets screwed into the underside of the countertop. This provides stability and prevents the appliance from tipping once installed.

To attach the bracket:

  • Hold it up to the quartz underside and mark the screw holes.
  • Drill pilot holes at the marks to prevent cracking.
  • Secure the bracket using the provided screws and tighten gently – overtightening can crack the quartz.

Connect Water, Power, and Drainage

With the dishwasher held snugly in place, connect the necessary utilities:

  • Attach the hot water line to the dishwasher inlet.
  • Connect the drain hose to the sink drain pipe or garbage disposal.
  • Run the power cord through the cabinet cutout to a nearby outlet.

Add Sealant

The final step is applying a thin bead of silicone sealant around the edges of the dishwasher:

  • Run the sealant along the top front edge where the counter meets the dishwasher.
  • Add sealant along the sides where the dishwasher meets the adjacent cabinets.
  • Use a smoothing tool to evenly distribute the sealant into a neat bead.

Let the sealant cure for at least 24 hours before running the dishwasher. The sealant prevents moisture and debris from getting under the appliance.

With careful prep and adjustment, a dishwasher can be seamlessly integrated into a quartz countertop installation. Always use caution and proper support to prevent damage to the engineered stone surface.

Frequently Asked Questions About Installing a Dishwasher with a Quartz Countertop

Can I install an undercounter dishwasher myself with a quartz countertop?

Yes, with proper preparation and care, an experienced DIYer can install their own undercounter dishwasher with a quartz countertop. The key is taking it slow, checking fit often, and adjusting the dishwasher height for a snug, gap-free fit.

How much space should I allow for the dishwasher in the cabinetry?

Standard built-in dishwashers are 18-24 inches wide. Allow 2 inches of space on either side for plumbing and electrical connections. The height from floor to underside of the counter should be 32.5 – 34.5 inches.

Should I cut the quartz countertop or order it pre-cut for the dishwasher?

It’s recommend to order a quartz countertop pre-cut with the proper sized opening for the dishwasher alcove. Attempting to cut the engineered stone yourself risks cracking or chipping.

What mounting bracket comes with the dishwasher for quartz installation?

Most undercounter dishwashers include a metal mounting bracket that gets screwed into the underside of the countertop to secure the appliance. Use the provided hardware and be careful not to overtighten.

How do I adjust the legs on the dishwasher?

There are adjustable legs at the front of the dishwasher. Use a wrench or pliers to turn the legs clockwise to raise the dishwasher or counter-clockwise to lower it. Adjust for a snug fit.

What kind of sealant should be used between the quartz and dishwasher?

A silicone sealant designed for kitchen and bath applications works best. Apply a thin bead after installation and let cure fully before running the dishwasher.


Installing a dishwasher into quartz countertops requires careful planning and precision. With the proper dishwasher model, adjusting the height for a flush fit, securing the mounting bracket, and sealing gaps, you can have a beautiful and functional kitchen appliance that seamlessly integrates with a quartz countertop. Taking it slowly and checking fit often is crucial to prevent any damage to the engineered stone surface. With some patience, the right materials, and proper care, you can enjoy the clean, integrated look of a dishwasher with quartz countertops.