How to Seal the Seams in Quartz Countertops

Why Sealing the Seams is Important

Sealing the seams creates a moisture barrier that prevents liquids and debris from getting underneath the countertop. This protects the adhesive and prevents warping, separation, or damage over time. Other reasons to seal the seams include:

  • Prevents bacteria, mold, and mildew growth in the seams
  • Minimizes staining and discoloration
  • Reduces uneven or inconsistent seam appearances
  • Strengthens the structural integrity of the countertop

Properly sealing the seams will maintain the beauty of your quartz countertops for years to come.

What You Need to Seal Quartz Seams

  • 100% silicone sealant designed for kitchen and bath use
  • Sealant applicator gun
  • Paper towels or rags
  • Nitrile gloves
  • Painter’s tape
  • Denatured alcohol
  • Mixing stick

Make sure to use a high-quality, 100% silicone sealant that states it can be used for kitchen and bath areas. Avoid general purpose or acrylic sealants. Purchase an applicator gun to easily control the flow of sealant.

Step-by-Step Guide

Follow these steps to properly seal the seams in your quartz countertops:

1. Clean and Dry the Seams

The seams need to be clear of any dirt, grease, oil, or other residues in order to achieve the best seal. Use denatured alcohol on a clean rag or paper towel to thoroughly clean each seam. Allow the seams to fully dry before applying sealant.

2. Prepare the Sealant

Follow the product instructions to load the silicone sealant tube into the applicator gun. Cut the tip of the tube to your desired bead size. Silicone beads between 1/8″ and 1/4″ width are common. Next, “wet” the tip by squeezing out a small amount of sealant and discarding it.

3. Tape the Seams

Apply painter’s tape along the edges of the countertop on both sides of each seam. This helps keep excess sealant from getting on the surface. Position the tape close to the seam without covering it.

4. Apply the Sealant

Run a steady, continuous bead of sealant along the length of each seam, holding the applicator gun at a 45° angle. Aim to keep the bead width consistent and make sure it fully penetrates the seam. Apply slightly more sealant than needed since it will settle after application.

5. Tool the Sealant

Before it skins over, use a mixing stick or putty knife to tool the sealant. Press the sealant into the seam to ensure it fully adheres and creates a smooth appearance. Remove any excess sealant with a rag.

6. Remove the Tape

Carefully remove the painter’s tape before the sealant dries. Try to pull it straight up and parallel to the countertop to avoid pulling sealant up. Remove residual sealant right away with denatured alcohol if needed.

7. Allow to Cure

Let the sealant fully cure according to the product directions. This is usually 24-48 hours. Avoid using the countertops during this time. Proper curing results in a durable, waterproof seal.

Sealing Quartz Seam Maintenance

  • Inspect the seams periodically and reapply sealant if any gaps, cracks, or shrinkage occur.
  • When recaulking, use the same process. Make sure to remove all old sealant before applying fresh sealant.
  • For routine cleaning, use a mild soap and water. Avoid abrasive cleaners or scouring pads.
  • Thoroughly dry the seams after cleaning to prevent water damage.

Properly sealing and maintaining the seams will help your quartz countertops last for many years. Let us know if you have any other questions!

Frequently Asked Questions about Sealing Quartz Seams

How long does quartz seam sealant last?

With proper application and curing, silicone sealant can last 3-10 years before needing replacement. Make sure to use a kitchen/bath formulated 100% silicone.

What’s the best sealant for quartz countertops?

We recommend using a pure silicone sealant made specifically for kitchen and bath areas. GE Silicone II is a top choice that provides long-lasting, flexible, waterproof sealing.

Should I seal quartz seams before or after installation?

It’s best to seal quartz seams after installation. This allows you to thoroughly clean the countertops and seams first. Sealing prior risks getting debris stuck under the sealant.

How long does it take for quartz seam sealer to cure?

Silicone sealants take 24-48 hours to fully cure. Avoid excess water and let the sealer set undisturbed during this time. Once cured, the seam is waterproof and ready for use.

Can I use clear caulk on quartz seams?

Yes, clear silicone caulk is a good option for sealing quartz seams to be less noticeable. Make sure it is 100% silicone, not acrylic latex caulk. GE Silicone I Clear is a reliable choice.

What color sealant should I use for white quartz?

For white quartz countertops, we recommend using a clear, transparent silicone sealant for the most invisible seams. Colored sealants like white or almond may stand out more.


Sealing the seams is a crucial step after quartz countertop installation to prevent moisture damage and maintain their durability. With the right silicone sealant and proper application technique, you can achieve long-lasting protection with minimal visibility. Be sure to keep the seams clean and reapply sealant as needed over the years. Let us know if you have any other quartz countertop sealing questions!