How to Fix Unlevel Quartz Countertop

Installing a quartz countertop can be a great way to upgrade your kitchen or bathroom. Quartz is an engineered stone that is non-porous, stain resistant, and easy to clean – making it a popular choice for countertops. However, sometimes quartz countertops may become unlevel over time due to settling or improper installation. The good news is that an unlevel quartz countertop can often be fixed fairly easily. Here is a step-by-step guide on how to fix an unlevel quartz countertop.

Assess the Situation

The first step is to assess just how unlevel your quartz countertop is. Place a level on the countertop to see if there are any noticeable high or low spots. Make note of which areas are higher or lower. Also check the underside of the countertop if possible to see if the substrate or support structure has become unlevel. This can help you identify what may be causing the issue.

Determine the Cause

There are a few common reasons why a quartz countertop may become unlevel:

  • Settling of the cabinetry or home. If the entire countertop is sloping in one direction, it is likely the cabinets or home have settled unevenly causing the countertop to become unlevel.
  • Improper installation. The countertop may not have been adequately supported or leveled during the original installation.
  • Warping of the substrate. If the plywood or other material under the quartz has warped or become unlevel, it can cause the countertop to become uneven.
  • Loose support braces. Countertops usually have support brackets underneath. If these have come loose, it can result in uneven spots.

Figuring out the cause will help determine the best solution. Inspect the areas thoroughly and use your best judgment.

Adjust the Substrate

If the substrate or support structure under the quartz has become unlevel, you may be able to re-level it to fix the issue. This often requires removing sections of the countertop to access the substrate.

Use shims to prop up any low spots in the cabinetry or substrate until they are even. You can also sand down any high spots on the substrate as needed. Re-secure any loose support braces.

Be very careful when handling the countertop pieces to avoid damaging the quartz. Make sure the substrate is completely level before reinstalling the countertop sections.

Re-secure the Countertop

If the countertop itself has become loose or unevenly supported, you may just need to re-secure it properly.

Apply a bead of silicone adhesive caulk along the underside perimeter of the countertop. Then re-tighten any brackets or clamps that hold the countertop in place on the cabinetry. Use shims to level the countertop as needed.

Allow the adhesive caulk to fully cure for at least 24 hours before using the countertop again. This should firmly re-secure the quartz to the substrate.

Use Shims for Minor Spots

For minor unlevel spots, you can often use shims to prop up the low areas of the countertop. Rubber, plastic, or wood shims can be inserted between the cabinetry and quartz countertop to level it out.

Be sure to use enough adhesive caulk to hold the shims firmly in place. Allow proper curing time. Check your work with a level to ensure the countertop is now even.

Consult a Professional

If your quartz countertop has major unevenness issues or the substrate itself is severely unlevel, it is best to consult a professional countertop installer. They have the skills, tools, and materials to adequately re-level or re-install your quartz countertop.

Hiring a professional avoids the risks of damaging your countertop during DIY leveling attempts. It may cost more upfront but give you peace of mind knowing the job is done right.

Prevention Tips

To help prevent quartz countertops from becoming unlevel in the future:

  • Make sure cabinets and home are properly leveled before installing countertops.
  • Use adequate support braces and brackets during installation.
  • Allow proper curing time for all adhesives and caulking.
  • Address any settling issues with the home right away before problems worsen.
  • Avoid placing excess weight in one area that could cause unevenness.
  • Have countertops professionally re-checked after any major settling or renovations.

With proper assessment and care, an unlevel quartz countertop can often be fixed or improved. Seek professional help for any severe leveling issues to get your countertop back to flat and functional.

Frequently Asked Questions

What are some signs my quartz countertop is unlevel?

Some signs your quartz countertop may be unlevel include visible sloping, rolling items like glasses or bottles move on their own, sinks not draining properly, or the countertop rocking when pressure is applied. Use a level to diagnose any unevenness.

Should I remove the whole quartz countertop to re-level it?

In most cases, you should not need to remove the entire countertop. Selectively remove sections as needed to access and fix the substrate. Removing the whole top increases the risk of breakage. Consult a pro if the entire substrate needs re-leveling.

Is it OK to shim a quartz countertop to level it?

Yes, using shims is an appropriate technique for leveling minor problem spots on a quartz countertop as long as they are properly secured with adhesive caulk. Avoid over-shimming which can put too much pressure in small areas.

Can I level my quartz countertop by sanding or grinding the surface?

It is not advisable to sand or grind the finished surface of the quartz. This can damage the appearance and integrity of the material. Shim or adjust the substrate instead.

Should I hire a professional if my quartz countertop is very unlevel?

In cases of major unevenness, hiring a professional countertop installer is highly recommended. They have specialized tools and experience to adequately diagnose and remedy significant leveling issues.


Uneven quartz countertops not only look unsightly but can lead to function issues. Thankfully, several effective DIY methods are available to fix unlevel quartz. Assessing the cause, adjusting the substrate, re-securing the top, and strategic shimming can often remedy minor to moderate unevenness. However, it is wise to enlist a professional installer for any pervasive quartz countertop leveling problems. With the right approach, your quartz countertop can be leveled to look and perform as good as new.