How to Eliminate Seam Marks on Quartz Countertops

Quartz countertops are popular choices for kitchen and bathroom remodels thanks to their durability, low maintenance, and attractive appearance. However, improper seaming during installation can result in unsightly seam marks that detract from the beauty of the countertop. Fortunately, there are several effective methods for eliminating seam marks on quartz countertops.

Why Seam Marks Occur on Quartz Countertops

Quartz countertops are made of crushed quartz aggregates held together with polymer resins. Slabs are cut from quarried blocks of engineered stone and then seamed together during installation. Seam marks occur when:

  • The seams are not flush, leaving an uneven ridge where the two slabs meet. This happens when the edges are not cut precisely.
  • There is excessive adhesive squeeze-out along the seam that dries and leaves an unsightly mark.
  • The slabs become misaligned during installation, creating a gap or overlap along the seam.
  • Grit and debris get trapped in the seam during polishing, resulting in a noticeable mark.

How to Remove Seam Marks on Quartz Countertops

Here are the most effective methods for eliminating seam marks on quartz countertops:


Gently sanding along the seam marks using successive grits of sandpaper can help level out uneven ridges. Start with a coarse grit like 80-grit to rapidly remove material, then follow up with finer 120-grit and 220-grit sandpaper to smooth out scratches. Take care not to sand too aggressively and compromise the structural integrity of the seam. Wipe clean with a dry cloth after sanding.


For adhesive squeeze-out along seams, allow the adhesive to fully cure first. Then use a plastic putty knife or the edge of a credit card to gently scrape off the excess dried adhesive. Take care not to dig into the surface of the countertop. Clean the area afterwards with denatured alcohol to remove any adhesive residue.


Using a handheld variable speed polisher with a foam pad, polish the seam marks and surrounding area with a quartz-specific polishing compound. Work your way up from coarser to finer grit compounds to restore the countertop’s smooth factory finish. Rinse thoroughly and buff dry.

Heat Treatment

A heat gun can be carefully applied to re-melt adhesive squeeze-out and level any uneven seams. Move the heat gun continuously over the area to avoid burning or discoloring the quartz. After heating, press the slabs back into alignment and allow the adhesive to cool and set.

Professional Help

For severe seam marks or countertop installation problems, consult with a professional countertop fabricator. They have specialized tools and materials to grind down stubborn seam marks and properly re-finish the area to blend in seamlessly with the rest of the quartz countertop.

Preventing Seam Marks During Installation

To avoid dealing with seam marks on your new quartz countertops, proper installation techniques are key:

  • Select an experienced, reputable countertop installer who pays close attention to seam details.
  • Ensure the countertop slabs are precisely cut along the edges to allow for a tight, flush seam.
  • Use minimal, non-dyed adhesive to reduce the chance of squeeze-out.
  • Clamp the slabs together securely as the adhesive dries to prevent movement or separation.
  • Carefully clean and polish the seams to remove any debris or adhesive residue.

FAQs About Eliminating Seam Marks on Quartz

How long should I wait before removing excess adhesive along seams?

It’s best to allow the adhesive to fully cure, usually 24-48 hours, before trying to scrape or peel it away. Removing it prematurely can damage the countertop surface.

What grit sandpaper is best for sanding down seam marks?

Start with 80-grit to rapidly grind down ridges, then smooth with 120 and 220-grit. Always sand lightly and avoid over-sanding any one area.

Can I use a quartz polishing kit to remove marks along seams?

Yes, a variable speed polisher and quartz polishing pads and compounds can help blend and minimize the appearance of seam marks.

Will staining or adding a finish help disguise seam marks?

Staining is not recommended for quartz, as it is difficult to achieve an even color. Clear finishes would likely draw more attention to the uneven surfaces along seams.

Should I try to remedy seam issues myself or call in a pro?

For anything beyond minor marks, it’s best to have a professional fabricator evaluate and repair significant seam issues to prevent making matters worse.


While seam marks on quartz countertops are fairly common and shouldn’t be cause for alarm, taking steps to remove them will keep your countertops looking pristine. With the proper tools and techniques, such as sanding, scraping, polishing, and heat treatment, you can eliminate unsightly quartz seam marks yourself or with professional help. Paying close attention to seaming during installation is also key to prevent problems down the road. With some effort and patience, your beautiful quartz countertop seams can disappear, restoring the elegant appearance you expect.