How to Install Quartz Floating Countertop

Installing a quartz floating countertop can transform the look of your kitchen or bathroom by creating a modern, sleek appearance. While it requires some specialized tools and techniques, installing a floating quartz countertop is a DIY-friendly project for many homeowners. Here is a step-by-step guide on how to install quartz floating countertop.

Choose the Right Quartz Slab

When selecting a quartz slab, consider the color, pattern, and thickness you want. Thicker slabs (2cm or 3cm) are recommended for floating installation to prevent sagging. For heavy use areas like kitchens, a 3cm slab is best. Choose an engineered quartz product like Caesarstone, Cambria, or Silestone made from roughly 90% ground quartz and 10% polymer resins. This man-made material is harder and more durable than natural stone.

Gather the Required Materials and Tools

You will need:

  • Quartz slab
  • Construction adhesive or silicone adhesive
  • Wall brackets
  • Shim blocks
  • Caulk/sealant
  • Drill
  • Circular saw with diamond blade
  • Router
  • Tape measure
  • Clamps
  • Denatured alcohol
  • Rags
  • Safety glasses and gloves

Prepare the Cabinet or Base

Ensure the cabinet or base you are installing on is level, secure, and able to support the full weight of the slab. Construct a 3/4″ plywood deck reinforced with brackets if needed. Cut the plywood to the exact dimensions of the interior cabinet frame. Check for level and make any adjustments.

Make Precise Measurements

Measure the exact dimensions of the cabinet interior. Mark the measurements on the backside of the quartz slab and cut the slab to size with a circular saw outfitted with a diamond blade. Cut very slowly to avoid cracking or chipping. The quartz should be 1/8″ smaller than the cabinet on all sides.

Cut Supports for Seamless Appearance

If installing multiple slabs side-by-side, cut support strips from 3/4″ plywood to place between the slabs. This provides extra support. Use a router with a rounded edge bit to create finished edges where the support strips will be located.

Dry Fit the Quartz

Carefully place the cut quartz slab into position on top of the plywood without any adhesive to check the fit. Look for any gaps at the edges or corners and make note of them. Remove the slab and plane or sand any edges that need adjustment.

Clean All Surfaces

Thoroughly clean all surfaces – the back of the quartz slab, the plywood deck, and the cabinet interior walls. Use denatured alcohol applied to clean rags. Remove any dust, oils, or debris that could interfere with proper adhesive bonding.

Apply Adhesive

Apply a generous bead of adhesive around the top edges of the plywood deck and in a grid pattern over the rest of the surface. Use dabs of silicone adhesive in each corner. Follow the adhesive manufacturer’s instructions.

Set Quartz in Place

Carefully lower the quartz slab into place with overhangs of 1/8″ on all exposed edges. Make sure adhesive makes contact evenly across the entire slab and deck. Use shims to adjust the quartz into the exact position wanted.

Secure Brackets

Attach wall brackets made for floating shelves along the wall edges every 8-12 inches. Position the brackets so they are hidden by the 1/8″ quartz overhang. Allow the adhesive to fully cure per manufacturer guidelines before attaching the brackets.

Complete Finish Work

Run a bead of silicone caulk along all seams and edges. Allow to dry fully. Carefully clean up any dried adhesive or caulk. Lastly, seal the quartz edges as the manufacturer recommends to prevent moisture intrusion. Enjoy your stunning new floating quartz countertop!

Frequently Asked Questions

How thick should a floating quartz countertop be?

For floating installation, a thickness of 2cm or 3cm is best to prevent sagging. 3cm is ideal for heavy use areas like kitchen countertops.

What adhesive works best for quartz countertops?

Construction adhesive or a premium silicone adhesive specified for quartz work well. Follow the adhesive manufacturer’s instructions.

Can you install a floating quartz countertop yourself?

With the right tools and preparation, installing a floating quartz countertop is totally DIY friendly. Just take care moving and cutting the heavy slab.

How much overhang should there be on a floating countertop?

A 1/8″ overhang on all exposed edges is recommended for quartz floating countertops. This allows brackets to be hidden.

Should you seal quartz countertops after installation?

It is highly recommended to apply a sealant to the edges of installed quartz countertops. This prevents moisture from seeping in and causing damage.


Installing a floating quartz countertop creates a sleek, modern look and is easier than a traditional overlay installation. With some simple DIY techniques, the right tools, and careful measurement, you can achieve professional-looking results. Be sure to choose an engineered quartz product in a thickness of 2cm or 3cm. Allow proper overhang space for hidden brackets. And don’t forget to seal the edges after installing. With this guide’s step-by-step instructions, you can successfully install stunning quartz countertops that flow seamlessly through your space.