How to Clean Grout: 5 Methods From Gentle to Heavy-Duty

Frequently Asked Questions

What's the best way to clean grout?

Baking soda + hydrogen peroxide paste for most household grout. Apply, wait 10-15 minutes, scrub with a stiff grout brush, rinse. For heavier stains: oxygen bleach (OxiClean powder mixed with warm water). For mildew and deep staining on white grout: diluted bleach (not on colored grout — it removes the pigment). Skip 'natural' vinegar methods — acid etches cementitious grout over time and makes it more porous, leading to faster re-staining.

Can I use bleach on colored grout?

No. Bleach strips pigment from colored grout, leaving white or pale patches that won't match the original color. Bleach is only safe on pure white grout, and even then it's harsh on the grout itself over repeated use. For colored grout, use oxygen bleach (OxiClean), hydrogen peroxide, or a pH-neutral grout cleaner. If colored grout has permanently darkened, grout colorant sealers can restore the appearance without removing the grout.

Does vinegar clean grout?

Vinegar cleans grout short-term but damages it long-term. Cementitious grout (the standard type) is alkaline; vinegar is acidic; acid etches the grout each time you apply it, making the surface more porous and more likely to stain again. Over years of vinegar use, the grout becomes chalky and weak. Baking soda + hydrogen peroxide achieves the same cleaning effect without the acid damage.

How often should I clean grout?

Wipe shower grout with a daily squeegee or microfiber cloth after showering (preventive — takes 60 seconds). Deep clean bathroom grout every 2-3 months. Kitchen backsplash every 1-2 months (grease buildup). Tile floors every 3-6 months depending on traffic. Apply penetrating sealer every 1-3 years (check by dropping water on grout — if it beads up, sealer is good; if it soaks in, reseal).

Should I clean or regrout?

Clean if the grout is just discolored, stained, or lightly mildewed. Regrout if grout is cracked, missing in sections, crumbling, or pulling away from the tile. Heavy mildew that cleaning can't reach (below the surface) is also a regrout candidate. Cleaning costs $5-$30 in supplies; regrouting a shower runs $300-$1,000 pro or $50-$150 DIY plus a full day. Worth cleaning first unless the grout is structurally failing.

How do I keep grout clean after cleaning it?

Three habits: (1) seal it — apply a penetrating silicone grout sealer after cleaning and every 1-3 years after. (2) squeegee showers after each use — reduces mildew buildup 80%. (3) ventilate bathrooms — run the exhaust fan during AND 20-30 minutes after showers. (4) regular light cleaning — a weekly spray with a tile and grout cleaner prevents buildup much better than a deep clean every 6 months.

Grout stains don’t just look bad — they indicate actual absorption of dirt, soap residue, and mold into the porous grout material. Left alone, stained grout becomes permanently discolored, starts to crumble, and eventually requires a full regrout ($300-$1,000 for a shower). The good news: 95% of grout stains clean up to nearly-new condition with 30-60 minutes of work and $15-$30 in supplies. This guide covers the 5 methods that work, the one common “natural” method that secretly damages grout, and the sealing habit that keeps it clean for years.

The 5 Methods That Actually Work

1. Baking Soda + Water (Light Daily Stains)

For: dust, light soap scum, day-to-day cleaning.

Mix baking soda with just enough water to form a thick paste. Apply along grout lines, wait 5-10 minutes, scrub with a toothbrush, rinse.

Cheapest option. Works on fresh stains. Won’t touch deep discoloration.

2. Baking Soda + Hydrogen Peroxide (Best All-Around)

For: most household grout stains.

Mix 3% hydrogen peroxide with baking soda until it’s a thick paste (2 parts baking soda to 1 part hydrogen peroxide). Apply, wait 10-15 minutes, scrub, rinse.

Hydrogen peroxide kills mildew and lifts organic stains; baking soda provides mild abrasion. Safe on both white and colored grout. Single best at-home grout cleaner.

3. Oxygen Bleach (OxiClean / Tide Oxi)

For: heavy mildew, stubborn stains, larger areas.

Mix OxiClean or similar oxygen bleach with warm water to a slurry. Apply generously, wait 15-20 minutes, scrub, rinse.

More powerful than baking soda + peroxide. Still safe on colored grout and colored tile (unlike chlorine bleach). Works on most brown/black grout staining.

4. Diluted Chlorine Bleach (WHITE Grout Only)

For: heavy mildew on white grout.

Mix 1 part regular household bleach with 4 parts water in a spray bottle. Spray on grout lines, wait 5-10 minutes, scrub, rinse thoroughly.

Only on white grout — bleach strips pigment from colored grout permanently. Ventilate well. Never mix with ammonia, vinegar, or other cleaners.

5. Dedicated Grout Cleaner (Heavy Commercial Stains)

For: neglected grout, kitchen grease buildup, heavy mildew.

Zep Grout Cleaner or Krud Kutter Tile and Grout Cleaner work on stains other methods can’t touch. Follow label directions — most require 5-10 minute dwell time.

Best for rental property deep cleans, kitchen backsplash grease removal, or “it looks worse every year” grout.

The Method to Avoid: Vinegar

Vinegar is popular in “natural cleaning” guides. It DOES clean grout short-term. Long-term, it damages it.

Why: Cementitious grout is alkaline (calcium-carbonate-based). Vinegar is acidic. Each application slightly etches the grout surface, making it more porous. More porous = absorbs stains faster = needs cleaning more often = more acid exposure = worse each cycle.

The result: grout that started white becomes gray or yellow, chalky texture, crumbles at corners, and starts releasing its pigment in colored grout.

The alternative: baking soda + hydrogen peroxide. Same cleaning effect, no acid damage. If you want to keep vinegar in your cleaning routine, save it for glass and bathroom fixtures (not grout).

The Right Brush Matters

• Standard grout brush ($3-$8) — narrow nylon bristles sized for grout lines. The default pick.
• Drill-mounted grout brush ($15-$30) — attaches to a cordless drill, cuts cleaning time 75% on larger areas. Worth it for tile floors or bathrooms with heavy grout.
• Electric grout scrubber ($25-$60) — specialized oscillating tool with narrow heads. Overkill for casual cleaning; worth it for annual deep cleans on large tile installations.
• Old toothbrush — free if you have one. Works but tires your hand out on anything over 10 square feet of grout.

Avoid wire brushes — they scratch both grout and tile.

The Sealing Step People Skip

Clean grout + no sealer = dirty grout again in 2-4 months. Clean grout + sealer = clean for 1-3 years.

Penetrating silicone grout sealer ($15-$30) soaks into the porous grout and creates a water-repellent layer without changing the color or appearance. Brands: Aqua Mix Sealers Choice Gold, StoneTech Heavy Duty Sealer.

Topical sealer ($10-$20) — sits on top of the grout, forms a visible film. Cheaper and easier to apply but wears off in 6-18 months. Only reasonable for low-use areas like backsplashes.

When to reseal: drop a few drops of water on grout. If it beads up, sealer is still working. If it soaks in within 10-15 seconds, reseal.

Timing: apply to fully dry grout (24-48 hours after cleaning, longer if humid). Most sealers need 24-48 hour cure time before water exposure.

Clean vs Regrout: The Decision

Clean if:

• Grout is stained/discolored but structurally intact
• Mildew is surface-level
• Grout lines are even thickness
• No crumbling or powdering

Regrout if:

• Grout is cracked, missing, or pulling away from tile
• Crumbling or powdering
• Mildew returns within weeks of cleaning (probably growing IN the grout, not on it)
• Tile is loose (often grout has failed behind)
• Previous regrout or patchwork is visible

Regrouting a shower is $300-$1,000 professional or $50-$150 DIY plus a full day of work. Cleaning first is always worth trying unless structural failure is obvious.

Room-by-Room Maintenance

Shower Grout

• Squeegee after every use (60 seconds, prevents 80% of future problems)
• Weekly: spray tile and grout cleaner, let sit 5 minutes, wipe
• Monthly: scrub problem spots with grout brush
• Quarterly: full deep clean with baking soda + peroxide
• Every 1-2 years: reseal

Kitchen Backsplash

• Wipe after any grease cooking (rasp oil stains before they set)
• Monthly: spray with tile and grout cleaner, scrub
• Quarterly: deep clean with oxygen bleach for grease + mildew
• Every 2-3 years: reseal (less traffic than shower)

Bathroom Floor Grout

• Weekly: vacuum/sweep to prevent abrasive dirt from grinding in
• Monthly: steam clean or manual scrub problem spots
• Quarterly: full floor grout scrub
• Every 2-3 years: reseal

Entryway and High-Traffic Floor Grout

• Daily: vacuum
• Weekly: mop with pH-neutral cleaner (not vinegar, not acidic products)
• Quarterly: deep grout clean
• Every 1-2 years: reseal

Fixing Persistently Dark or Yellow Grout

Sometimes grout cleans but doesn’t brighten fully. Options:

1. Grout colorant ($15-$30) — essentially paint for grout. Applied after thorough cleaning, restores color, and seals in one step. Works on both white and colored grout. PolyBlend Grout Renew is the widely-available pick.

2. Oxygen bleach soak — wet the grout, apply a thick oxygen bleach paste, cover with plastic wrap, let sit 2-4 hours, scrub, rinse. Extended dwell pulls out stains other methods can’t.

3. Steam cleaning — handheld steam cleaner ($50-$150) uses superheated steam to lift embedded dirt. Effective but slow.

4. Regrout — if none of the above work, the staining is inside the grout itself. Full regrout is the only true fix.

Safety Rules

• Ventilate when using any grout cleaner — even “gentle” ones can irritate lungs
• Never mix cleaners — bleach + ammonia = toxic gas, bleach + vinegar = chlorine gas
• Protect natural stone — marble, limestone, travertine tile is etched by most grout cleaners; test in an inconspicuous area first
• Wear gloves — even baking soda + peroxide dries skin
• Keep pets and kids out during cleaning and dwell time

When to Hire a Pro

Most grout cleaning is DIY. Hire a pro if:

• Large area (over 500 sq ft of tile)
• Heavily textured tile that catches cleaner
• Natural stone (marble, travertine) — professional technique prevents etching
• You want deep-steam cleaning (commercial units work much better than rentals)
• Physical mobility limitations (scrubbing floors is hard)

Professional grout cleaning: $0.50-$2.00 per square foot. A typical bathroom (60 sq ft of tile) runs $60-$150. Worth it for large projects; skip for small bathrooms you can handle in an afternoon.

Related Reading

• How to Grout Tile — the full grouting process for new tile installation
• How to Caulk a Bathtub — the other bathroom seam maintenance task
• How to Install a Tile Backsplash — new tile project that includes proper grout sealing from day one
• How to Clean a Dishwasher — similar monthly-maintenance mindset
• How to Clean a Washing Machine — another appliance/fixture maintenance routine
• Best Paint for Bathroom Walls — companion bathroom finish care
• Small Bathroom Remodel Ideas — when cleaning isn’t enough and you want a refresh
• Bathroom Remodel Cost Breakdown — full-project pricing