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Can you stain existing grout?

Grout is the material used to fill in the gaps between tiles on floors, walls, countertops, and other tiled surfaces. Over time, grout can become discolored, stained, cracked, or just look dirty and dated. While replacing the grout entirely is an option, many homeowners want to know if they can simply stain or color the existing grout to refresh the look without a major renovation project.

What is Grout?

Grout is a cement-based material used to fill the joints between tiles. It creates a waterproof seal that prevents moisture from getting under the tiles and causing damage. Grout also helps secure the tiles in place.

There are two main types of grout:

  • Sanded grout – contains fine sand and is used for joints wider than 1/8 inch. Most commonly used with ceramic and porcelain floor tiles.
  • Unsanded grout – smooth, without sand. Used for narrow grout lines 1/8 inch or smaller. Often used with glass tiles and on walls.

When grout is newly installed, it has a uniform color and finish. But over time it can become stained, discolored, crack, or appear dirty due to mold and mildew buildup in the porous surface.

Can You Stain Existing Grout?

Yes, it is possible to stain existing grout. Special grout stain products are formulated to penetrate into the pores and change the color of the grout. Staining can provide a dramatic facelift for old, dirty grout.

There are two main categories of grout stain:

  • Dye stains – contain liquid dyes that are absorbed into the top layer of the grout. Less expensive and easier to apply than epoxy stains.
  • Epoxy stains – contain colored epoxy resins that seal and color the grout. Provides a durable and permanent color change.

Benefits of Staining vs. Regrouting

Staining existing grout offers a few advantages over regrouting:

Staining Regrouting
  • Less expensive
  • Faster – no prep or drying time
  • No special tools or caulk needed
  • No grout haze to clean up
  • Permanent solution
  • Can fix cracks and flaws
  • Wide color selection

As the table shows, staining is generally an easier and cheaper option than completely regrouting. However, for badly damaged or deteriorated grout, a full regrouting may still be necessary.

What Type of Grout is Best for Staining?

The best types of grout for accepting stain are:

  • Sanded cement grout – staining penetrates well into the sandy texture.
  • Unsanded cement grout – smoother finish allows for uniform staining.
  • Polyblend grouts – contain polymers that allow stains to adhere evenly.

Epoxy grouts are not able to be stained because the epoxy resin seals the surface. Grout with a smooth polished finish will also not take stain well.

How to Prepare Grout for Staining

Proper preparation is key to achieve uniform grout staining results. Here are some tips for getting grout ready for stain:

  • Clean thoroughly – use a grout brush and cleaning agents to remove dirt, grime, mold, mildew, and existing sealers from the surface.
  • Rinse well – it’s important to remove any residue that could block the stain from penetrating.
  • Let dry completely – do not apply stain until grout is completely dry.
  • Apply grout sealer – seal the cleaned grout first with a penetrating sealer to protect pores from absorbing stain unevenly.

Taking these steps helps the grout absorb the new color evenly. Always test stain in an inconspicuous area first to ensure compatibility with your specific grout type.

Tips for Applying Grout Stain

Follow these tips for best results when applying grout stain:

  • Carefully follow the product instructions for application methods and drying times.
  • Use a grout brush or paintbrush to apply an even coat and work the stain into the grout lines.
  • Apply in a back and forth motion across grout lines to prevent blotchiness.
  • Maintain a wet edge and work in small sections to prevent overlap marks as you go.
  • Wipe up any excess from tile surfaces immediately using a clean, damp cloth or sponge.
  • Allow stain to dry fully before applying a second coat if needed for darker color.
  • Seal with a grout sealer once the final coat has dried.

Properly prepping and taking care during application can help achieve professional looking results. Consider doing a test in a small area first.

How Long Does Grout Stain Last?

When applied correctly to suitable grout, a grout stain can last for years before needing to be reapplied. However, the lifespan depends on several factors:

Factor Impact on Grout Stain Lifespan
Type of stain Epoxy stains last longer than dye stains
Sealer applied Sealed grout better resists wear, scuffs, and fading
Location More exposure to sunlight, moisture, and traffic means more frequent reapplication needed
Cleaning methods Harsh cleaners can cause premature fading

With proper care, epoxy stain on a floor or counter area may only need refreshing every 5-10 years. A dye bathroom wall stain may need to be redone more frequently. Be sure to use gentle cleaners and reapply sealer periodically.

What Mistakes to Avoid When Staining Grout

There are a few common mistakes that can result in blotchy or poor staining results:

  • Not cleaning and preparing grout properly first
  • Using too much stain or applying too heavily
  • Failing to wipe up stain completely from tile surfaces
  • Not allowing proper drying time between coats
  • Applying stain in direct sunlight or on hot surfaces
  • Not sealing after staining

Rushing the process or using the wrong applicator can also cause an uneven finish. Taking your time and carefully following product instructions can help avoid any staining mishaps.

Removing Existing Grout Stain

Removing an existing grout stain is difficult but not impossible. Here are some options to try:

  • Abrasive cleaners with active ingredients like chlorine bleach or oxygen bleach may help lighten or remove some dye stains.
  • Acids such as phosphoric, muriatic, or sulfamic acid can etch away the top layer of cement-based grout and old stain. Use proper precautions for handling acids.
  • Grinding with a Dremel tool and grout removal bit will abrade off the stained grout layer.
  • As a last resort, the grout could be completely removed either manually or with a grout saw and then replaced with new grout.

Trial and error may be needed to find the right removal method for the specific type of grout stain. Protect tile surfaces and test in an inconspicuous spot first.


Staining is an inexpensive way to refresh old grout and change the color. With proper preparation and application, a grout stain can last for years before needing to be redone. Pay attention to the prep steps, work slowly and carefully, and seal at the end for best results. Avoid common mistakes like sloppy application and insufficient drying times. Consider completely regrouting if the existing grout is severely damaged or deteriorated. With some time and care, staining existing grout can give tilework a brand new look.