How to Apply Grout Sealer on Backsplash


A backsplash is a practical and decorative feature in kitchens and bathrooms. Typically made of tile, stone, or other materials, a backsplash protects the walls from moisture damage and spills while adding visual interest. Over time, the grout between backsplash tiles can become discolored, stained, or allow moisture to seep through. Applying a penetrating grout sealer creates an invisible barrier that keeps stains and moisture from absorbing into the grout. Sealing grout can extend the life and maintain the beauty of any tiled backsplash.

Benefits of Sealing Grout

Sealing grout provides many important benefits:

  • Prevents stains: Spills and splatters from cooking or cleaning can quickly stain light grout. A grout sealer creates a protective barrier.
  • Reduces moisture absorption: Grout is porous and will absorb water and humidity over time. This moisture can lead to mildew and damage the grout. Sealing prevents absorption.
  • Extends the life of grout: By protecting grout from damage, sealing can keep it looking new for many extra years. Re-sealing every 1-2 years extends this protection.
  • Maintains appearance: Sealed grout maintains its original color much longer. Unsealed grout often becomes darkened and discolored prematurely.
  • Healthier environment: Sealing grout helps prevent mold and mildew growth by blocking moisture. This contributes to better indoor air quality.

When to Apply Grout Sealer

New Grout

It is highly recommended to seal new grout during initial tile installation. Applying sealer on clean, new grout allows maximum penetration and protection right away. Waiting to seal later allows the grout to absorb more contaminants that cannot be removed.

Existing Grout

For existing grout, it is ideal to seal it every 1-2 years. Sealing worn and heavily used grout will revitalize the appearance and prevent further damage. Kitchen backsplash grout near stoves may need sealing more frequently than other areas.

Signs that existing grout needs sealing include:

  • Discoloration or staining
  • Crumbling, cracking, or powdery grout
  • Absorbed food, oil or grease stains
  • Hazy dullness or fading color
  • Grout appearing lighter than surrounding tiles
  • Increased moisture damage or mildew growth

Sealing at the first signs of wear or discoloration will provide the best protection.

After Grout Cleaning

It is important to seal grout again after deep cleaning. The cleaning process will break the previous seal and open the pores of the grout. Sealing after cleaning will refresh the protective barrier.

What You Need to Apply Grout Sealer

Sealing grout is an easy process that requires minimal supplies:

  • Grout sealer – Select a penetrating/impregnating sealer for interior tile. Topical sealers tend to wear quickly and require frequent reapplication.
  • Small foam brush or paintbrush
  • Lint-free cloths
  • Painter’s tape
  • Tray or plate

Optional handy items:

  • Rubber gloves and eye protection
  • Knee pads
  • Headlamp for better lighting

Avoid using siliconized acrylic sealers which can discolor grout. Instead select a penetrating sealer made for grout and natural stone. Common types are epoxy or urethane formulations. Always check the product label to verify suitability for grout application.

Prep Steps Before Sealing Grout

Proper preparation is crucial for the sealer to adhere and perform properly:

Clean the Grout

Grout must be thoroughly cleaned before sealing. Existing sealers, films, dirt, grease, soap scum, and any other contaminants will prevent penetration. Clean with a tile & grout cleaner or make a baking soda paste. Rinse well and allow to dry fully.

Check for Cracks and Damage

Cracks, chips, holes, and missing grout should be repaired before sealing. Use a grout saw to remove old grout and re-grout any problem areas. Allow repairs to cure completely before sealing.

Tape Off Surrounding Areas

Use painter’s tape to cover the edges of countertops, walls, appliances, or any adjacent surfaces. This prevents them from accidentally being sealed or stained.

Ensure Grout is Dry

Sealer cannot penetrate into damp grout. Test for dryness by taping a plastic bag or plastic wrap securely to the grout. If condensation appears on the underside, then it is still too damp to seal. Allow additional drying time.

Once prepped, the grout is ready for sealer application. Follow all safety precautions on the sealer product labeling. Work in sections for easiest coverage.

How to Apply Grout Sealer

Step 1 – Prepare the Sealer

Pour a small amount of sealer into a tray or plate to use as a dipping vessel. Close the container tightly since air exposure can ruin unused sealer. Have lint-free cloths or paper towels ready to wipe away excess.

Step 2 – Apply Sealer

Dip a small foam or paintbrush into the sealer tray just deep enough to dampen the tips of the bristles. Apply a thin, even layer of sealer directly onto the grout lines. Avoid brushing sealer onto the tile faces – focus only on grout lines. Re-dip the brush periodically to maintain a wet edge.

Step 3 – Wipe Away Excess

Before the sealer dries, use a cloth to gently wipe any puddles or excess off the tile faces. Wipe diagonally across the grout lines to prevent also wiping sealer out of the joints. Work in small sections for easiest wipe-up.

Step 4 – Allow Proper Cure Time

Refer to the product directions for specific cure times. Most penetrating sealers require 30-60 minutes curing before becoming water and stain resistant. Avoid walking on or cleaning freshly sealed grout during this period. Insufficient cure times can prevent the sealer from achieving full effectiveness.

Step 5 – Apply Second Coat If Needed

One coat is often sufficient for grout sealing. For very porous or deteriorated grout, applying a second coat after the full initial curing time will provide maximum protection.

Step 6 – Remove Tape and Clean Up

Once fully cured, carefully remove all painter’s tape from countertops, walls, and surrounding surfaces. Remove any sealer residue with a damp microfiber cloth and mild cleaner if needed. Rinse thoroughly and wipe any remaining moisture with a dry cloth.

Tips for Applying Grout Sealer

  • Use a color enhancing sealer on white or light colored grout to keep it looking bright white.
  • Apply sealer when humidity is low. High humidity can disrupt proper curing.
  • Thoroughly shake or stir sealer before use and periodically during application. Sealers can settle over time.
  • Work under adequate lighting so coverage is completely visible. Natural light is ideal.
  • Maintain a wet edge and move quickly from section to section. Do not allow sealer to partially dry before wiping up excess.
  • If sealer residue needs removal after curing, use a pH neutral cleaner or dilute white vinegar solution. Avoid harsh chemicals. Test in an inconspicuous area first.

Frequently Asked Questions

What is the difference between sealing and grout cleaning?

Cleaning removes dirt, stains, and contaminants from the surface of the grout. Sealing applies a protective coating to seal the pores against future absorption of moisture and stains. Cleaning prepares the grout for sealing. Both are needed to revitalize grout.

How soon can I get the backsplash wet after sealing?

Follow the product label for specific cure times, but most sealers reach full water repellency within 1-2 hours after application. Avoid direct water contact for 24 hours when possible.

How long does the sealer last?

Durability depends on the sealer quality and amount of use and wear. Typically grout sealers last 1-5 years before requiring reapplication. Heavily used kitchen backsplash grout may need sealing yearly.

Can I seal only part of my backsplash?

It is best to seal all grout lines in the entire backsplash at the same time for uniform appearance and protection. The sealed portion will look noticeably different from unsealed areas.

How do I know if I need to reseal?

Signs like fading, discoloration, absorption stains, or increased moisture damage indicate that the sealer barrier has worn off and grout needs resealing. These symptoms often appear gradually over 1-2 years.

Can any sealer work on grout?

No. Topical acrylic sealers do not work well on grout joints. Only penetrating sealers formulated for grout and masonry provide effective grout sealing. The product label should specify grout usage.

Maintaining Sealed Grout

Proper maintenance is key for long-lasting sealer durability:

  • Use a pH neutral daily cleaner instead of harsh chemicals or bleach that can degrade sealer effectiveness more quickly.
  • Immediately wipe any spills once cured to prevent possible stains.
  • Avoid abrasive scrubbing of sealed grout which can slowly erode the protective layer.
  • Re-apply sealer every 1-2 years based on condition and usage levels.
  • Watch for any breaches in sealant from damage or repairs. Immediately re-seal any problem areas.


Sealing a backsplash grout revitalizes the color, prevents damaging moisture absorption, and provides stain protection.
While sealing requires minimal supplies and effort, proper preparation and application technique are vital to achieve maximum performance and longevity of the protective sealer barrier. With proper sealing and maintenance, your backsplash can maintain a like-new appearance for many years before requiring regrouting.