How to Seal Granite Countertops

Protect your granite countertops by sealing them properly

By
Lee Wallender
Lee Wallender
Lee Wallender

Lee has over two decades of hands-on experience remodeling, fixing, and improving homes, and has been providing home improvement advice for over 13 years.

Learn more about The Spruce's Editorial Process
Updated on 11/25/23
sleek kitchen with stainless appliances and dark wood cabinets
Beautiful Modern kitchen with a counter height bar Jodi Jacobson/E+/Getty Images
Project Overview
  • Working Time: 20 - 40 mins
  • Total Time: 1 - 2 hrs
  • Yield: Strip and reseal one granite countertop
  • Skill Level: Beginner
  • Estimated Cost: $25 to $50

Granite countertops, while hard, are surprisingly absorbent. Just as wood has its grain, stone has its pores. Synthetic surfaces such as Corian, solid surface, or quartz are often better than natural stone for their impermeability. Granite countertops for kitchens or bathrooms are not usually the most practical option; they are more of an aesthetic choice for their natural beauty. Fortunately, it's easy to seal a granite countertop.

Most granite countertops will need sealing; however, if you have highly polished granite, the high-gloss countertop might not need sealing. Check with the manufacturer since most will seal a new countertop.

Here's how to seal a granite countertop; it takes a few minutes and requires little more than a granite sealer and a clean pad.

Water-Based vs. Solvent-Based Sealants

Water-based and solvent-based sealants are applied the same way. The main differences are the ingredients and how long they last.

Water-based sealants are friendlier for the environment than solvent-based sealants, containing fewer volatile organic compounds (VOCs). However, the ingredients may still include urethane, acrylic, silanes, siloxanes, and fluoropolymers.

A significant downside is that water-based sealants do not last very long, usually requiring reapplication every six to 12 months. It helps that water-based sealants cost less—about $15 for a 24-ounce spray bottle. Other significant benefits of water-based sealers are that they are non-flammable and have no strong solvent odor.

Comparatively, a solvent-based sealant can cost about $50 but might only need application every five to 10 years. It does a better job of penetrating the stone, while water-based sealers are more topical. Solvent-based sealers also appear glossier than water-based solvents.

What You'll Need

Equipment / Tools

  • 5 microfiber pads
  • 5 microfiber towels
  • 1 nylon scrubbing pad or fine steel wool

Materials

  • 1 bottle granite sealer
  • 1 bottle granite cleaner

Instructions

  1. Strip Off Old Sealer If Necessary

    It should not be stripped off unless the old sealer is sticky, hazy, or otherwise in bad condition.

    • Begin with very fine steel wool and rub gently if you need to strip off old sealer.
    • Alternatively, chemical strippers applied with a nylon scrubbing pad may help to strip off the old sealer.

  2. Clean the Surface

    The granite must be cleaned before sealing, regardless of whether or not the old sealer was removed.

    • Spray a daily granite cleaner on the surface.
    • Wipe off with microfiber pads. Before proceeding to the next step, the pads must come up clean (no dirt or residue).

  3. Prepare to Apply Sealant

    • Read the instructions before applying the sealant to confirm it is appropriate for your granite type.
    • Prepare the room. Whether you choose water- or solvent-based sealants, both are made with chemicals, so ensure the room has adequate ventilation by opening the windows.
    • Put on gloves.

  4. Test the Sealant

    • Test a small part of the surface before applying the sealant over the entire surface to ensure it won't mar the finish.
    • Check it within 20 minutes; the stone needs time to absorb the sealant.
    • If it looks good, apply the sealant to the rest of the surface.

  5. Spray the Granite Surface

    Spray the granite countertop in 2-foot-square sections.

    A little granite sealer usually goes a long way. A few squirts are generally enough to coat an average-sized kitchen or bathroom counter thoroughly. Two or three coats will be needed, but you will find that each subsequent coat spreads even a little bit further and soaks in less.

  6. Wipe the Granite Surface

    Wipe off the sealer with the microfiber padimmediately after spraying the granite. Do not let the sealer sit on the surface for long, as hazing may occur.

  7. Buff the Surface

    Buff the surface to a smooth glossy finish with a clean microfiber towel.

  8. Repeat Coats

    Apply up to three coats of sealer. One coat of granite sealer is not enough if the granite has been completely stripped of sealer.

Tips for Removing Stains from Granite Counters

Restoring a granite countertop can cost up to $60 per square foot. However, some stains can be removed from granite by making a simple poultice.

  • Make a paste mixture of hydrogen peroxide and diatomaceous earth. Place it over the stain. Diatomaceous earth is an inexpensive sedimentary rock that can be purchased in small bags online for $10 to $20.
  • Cover this with plastic wrap and seal the edges of the plastic with masking tape. Leave it on the stone for a couple of days.
  • Remove the plastic wrap and let the paste dry. Repeat if necessary. Also, sometimes, bleach can be added to the mixture.

When to Call a Professional

A countertop fabrication and installation company dealing with natural stone can help strip old granite sealer and apply new sealer. Professional sealing can cost up to $20 per square foot to seal.

Even if you plan to apply sealer yourself in the long term, you may want to have the first sealer done by professionals.

FAQ
  • What is the best way to strip a sealant from the granite?

    Use mineral spirits, isopropyl alcohol, or acetone to remove the sealer from the granite countertop. Call a countertop technician with natural stone cleaning experience if none works.

  • Do all granite countertops need to be sealed?

    Most granite countertops need to be sealed unless previously sealed at the factory or if highly polished. Also, many countertop surfaces that appear to be granite aren't. Quartz countertops often look like natural stone yet should not be sealed.

  • What do you use to permanently seal granite countertops?

    You cannot permanently seal granite countertops. But some granite sealers last longer than others. The best way to ensure that your granite sealer will last a long time is by properly stripping (if needed) and cleaning the granite. You also need to ensure that enough sealer coats have been applied.

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