How to Clean Tile Grout
Tile grout collects soap residue, cooking grease, hard-water minerals, and mildew, which can make otherwise clean floors and walls look worn.
Knowing how to clean tile grout correctly helps restore color, improve hygiene, and extend the life of ceramic, porcelain, and stone tile installations.
The best method depends on the grout’s condition, the type of stain, and whether the grout is sealed, so a one-size-fits-all approach often misses the mark.
This guide explains practical cleaning methods, safe products, and the mistakes that can damage grout over time.
What grout is and why it gets dirty
Grout is the porous material that fills the joints between tiles, usually made from cement-based compounds or epoxy.
Because cement grout absorbs liquids and traps fine debris, it stains faster than tile surfaces and often darkens in high-traffic or damp areas.
Common causes of grout discoloration include:
- Soap scum and body oils in showers and tubs
- Grease and food splatter in kitchens
- Mold and mildew in humid rooms
- Soil and grit tracked across floors
- Hard-water deposits around sinks and fixtures
Before choosing a cleaner, identify whether the discoloration is surface dirt, embedded staining, or biological growth.
That distinction determines whether scrubbing, whitening, disinfecting, or re-sealing will be most effective.
Supplies you need to clean tile grout
Most grout-cleaning jobs can be handled with basic tools and a few household products.
Using the right brush and cleaning solution matters more than using harsh chemicals.
- Soft-bristle grout brush or old toothbrush
- Microfiber cloths or mop
- Spray bottle or small bucket
- Baking soda
- Liquid dish soap
- Hydrogen peroxide
- White vinegar for non-stone tile only
- Commercial grout cleaner for tough stains
- Rubber gloves
If the tile is natural stone such as marble, limestone, travertine, or slate, avoid acidic cleaners like vinegar and many citrus-based products.
Acid can etch stone and weaken the surrounding grout.
How to clean tile grout with a baking soda paste
A baking soda paste is a reliable first step for moderately dirty grout because it lifts grime without scratching most tile surfaces.
It works well on bathroom walls, kitchen backsplashes, and lightly soiled floors.
- Mix baking soda with a small amount of water until it forms a spreadable paste.
- Apply the paste directly to the grout lines.
- Let it sit for 5 to 10 minutes so the residue softens.
- Scrub with a grout brush using short, firm strokes.
- Wipe clean with a damp microfiber cloth.
- Rinse the area with clean water and dry it thoroughly.
For extra cleaning power, add a few drops of dish soap to the paste.
The soap helps break down greasy residue, especially in kitchens.
How to clean tile grout with hydrogen peroxide?
Hydrogen peroxide is useful for whitening grout and reducing mildew stains, especially when the grout looks dingy after normal cleaning.
A 3% solution, commonly sold in pharmacies and grocery stores, is usually strong enough for household use.
- Pour hydrogen peroxide into a spray bottle or apply it directly to the grout.
- Let it sit for 5 to 15 minutes depending on the stain.
- Scrub the grout with a brush.
- Wipe away residue and rinse with clean water.
For stubborn stains, mix hydrogen peroxide with baking soda to create a thicker paste.
This combination clings to vertical surfaces better than liquid cleaners and can brighten discolored grout lines with repeated use.
Can you use vinegar to clean grout?
White vinegar can help remove soap scum and mineral buildup on ceramic and porcelain tile, but it should be used carefully.
Vinegar is acidic, so it is not appropriate for natural stone surfaces or for frequent use on older, damaged grout.
If the surface is safe for vinegar, mix equal parts white vinegar and water in a spray bottle.
Spray the grout, wait a few minutes, scrub gently, and rinse well.
Never mix vinegar with bleach or ammonia, and never combine it with products you do not understand.
Because repeated acid exposure can weaken cement-based grout, reserve vinegar for occasional deep-cleaning jobs rather than routine maintenance.
How to clean heavily stained grout
Deep stains often require a more aggressive approach than a simple household paste.
If the grout remains dark after scrubbing, the stain may be embedded in the pore structure or caused by mold below the surface.
Use this process for stubborn stains:
- Pre-clean the area to remove loose dirt.
- Apply a commercial grout cleaner labeled for your tile type.
- Allow the product to dwell for the recommended time.
- Scrub in small sections with a grout brush.
- Rinse thoroughly to remove all cleaner residue.
For old discoloration, oxygen bleach products can be effective on grout because they lift organic stains without the harshness of chlorine bleach.
Follow the label instructions carefully and test in an inconspicuous area first.
How to clean mold and mildew from grout?
Mold and mildew thrive where moisture lingers, such as shower corners, bathtub surrounds, and poorly ventilated laundry rooms.
Cleaning the surface is only part of the solution; reducing humidity is essential to prevent recurrence.
To remove mold and mildew:
- Ventilate the room with open windows or exhaust fans.
- Apply hydrogen peroxide or a mold-safe grout cleaner.
- Let it dwell long enough to break down biological growth.
- Scrub the grout and rinse thoroughly.
- Dry the area completely with a towel or fan.
If the growth returns quickly, the grout may need resealing or replacement, especially if water is penetrating behind the tile.
How to clean grout on floors without damaging tile
Floor grout often accumulates dirt from shoes, pets, and spills, but excessive water can seep into joints and create larger problems.
Use a damp cleaning method rather than soaking the entire floor.
Best practices for floors include:
- Vacuum or sweep before scrubbing
- Work in small sections
- Use a lightly damp brush, not a dripping one
- Wipe up dirty water as you go
- Dry the floor after cleaning
For large areas, a steam cleaner can help loosen grime in durable tile installations.
Check manufacturer guidelines first, because some grout lines, sealers, and tile finishes may be sensitive to heat and moisture.
How to keep grout clean longer
Regular maintenance is the easiest way to avoid frequent deep-cleaning sessions.
Clean grout lasts longer, looks brighter, and is less likely to harbor odor-causing buildup.
- Wipe spills quickly, especially in kitchens and bathrooms
- Use pH-neutral tile cleaners for routine mopping
- Run ventilation fans during and after showers
- Dry shower walls and floors when possible
- Re-seal cement grout on the schedule recommended by the manufacturer
Sealing does not make grout stain-proof, but it slows absorption and gives you more time to clean spills before they set.
If water no longer beads on the grout, it may be time to reseal.
When to call a professional tile and grout cleaner
Professional cleaning is worth considering when stains remain after repeated home treatment, when mildew keeps returning, or when the grout is so dark that it no longer responds to standard cleaning.
A professional may use high-pressure extraction, specialty alkaline cleaners, or color sealing to restore a uniform appearance.
Call a specialist if you notice:
- Cracked, crumbling, or missing grout
- Persistent black staining after cleaning
- Water damage under tile
- Loose tiles or hollow sounds beneath flooring
- Discoloration in natural stone installations that require specialized care
Knowing how to clean tile grout starts with matching the cleaner to the stain and the surface.
With the right approach, most grout can be restored without replacing the tile or using overly harsh chemicals.