How to Seal Countertops

A stone sealer helps reduce absorption of liquids into natural stone, making it more resistant to staining. It buys time to wipe up spills before they penetrate the surface.

No. Sealing makes stone stain-resistant, not stain-proof. Liquids left sitting, especially oils, wine, coffee, or acidic substances—can still penetrate and discolor stone over time.

Frequency depends on the stone and how heavily the area is used. General guidelines: 

• Granites and Quartzites: every 1–2 years
• Marble/Limestone: every 6–12 months
• Some stones may require less, or more frequent sealing based on porosity.

Perform a simple water test:

• Place a few drops of water on the surface.
• If the stone darkens within a few minutes, it’s time to reseal.
• If the water stays beaded on top, the sealer is still working.

No. Etching happens when acids react with calcium in marble, dulling the surface. Because etching is a chemical reaction, not absorption, sealers cannot stop it.

No. Sealers vary in strength, durability, and absorption depth. Most used are impregnating/penetrating sealers, which protect below the surface without forming a film.

Yes, most homeowners can apply penetrating sealers. However, professional application is recommended for:

• Large areas
• Highly porous stones
• Re-polishing or refinishing marble

Most penetrating sealers are invisible and do not alter the appearance. "Enhancing sealers" deepen the stone’s color and give a “wet look” but are optional.

The application itself takes 15–30 minutes. Most sealers require:

• A short dwell time (5–15 minutes)
• Wiping excess
• Cure time (4–24 hours), depending on the product
• Some brands require multiple coats depending on stone color.

Unsealed stone is more susceptible to:

• Staining
• Moisture absorption
• Faster wear
• Darkening from oil or grease
• Mineral buildup

No. Quartz (engineered stone) is non-porous and does not require sealing. Only natural stones require sealing.

Sealing helps with water absorption and staining, but outdoor stone is still exposed to:

• UV light
• Weather changes
• Mineral deposits
• Regular cleaning and periodic resealing are recommended for exterior installations.

No. Stains must be removed before sealing—typically using a poultice or stone-safe stain remover. Sealer then helps prevent future staining.

Depending on stone type, use, and the sealer, protection typically lasts:

• 6 months to 3 years for indoor surfaces
• 6–12 months for outdoor or high-use areas.