How to Clean Grout on Tile Floors: 5 Methods From Gentle to Heavy-Duty (2026)

You can mop a tile floor every day and it'll still look dirty if the grout lines are dark. Grout is porous — it absorbs water, soap residue, food spills, and foot grime, then holds onto all of it. The good news: even badly stained grout cleans up dramatically with the right approach. The trick is matching the method to how stained it is and what kind of grout you have.

Below are five methods, ranked from gentle to aggressive. Start at the top, escalate only if needed. Skip the steam cleaner and bleach if you have unsealed or colored grout — we'll explain when each is safe.

Before You Start: Two Questions

1. Is your grout sealed or unsealed?

Most professionally-installed tile has sealed grout (a clear penetrating sealer applied within 72 hours of installation). Sealed grout is forgiving — acids and bleach won't immediately damage it. Unsealed grout absorbs everything, including cleaners, which can leave streaks or strip pigment.

Quick test: drop a small amount of water on a grout line. If it beads up or rolls off, it's sealed. If it soaks in within 60 seconds, it's unsealed or the sealer has worn off (typical after 3–5 years).

2. Is your grout cement-based or epoxy?

• Cement (sanded or unsanded): the standard, porous, comes in many colors. Absolutely needs sealing.
• Epoxy: non-porous, almost stain-proof, doesn't need sealing. Looks slightly plasticky. Common in commercial kitchens and modern showers.

Epoxy grout barely stains — if it looks dirty, it's surface grime that wipes off with a damp cloth and dish soap. Skip the rest of this guide and just clean it. Methods below are for cement grout.

What You'll Need

• Baking soda
• White vinegar
• Hydrogen peroxide (3%)
• Dish soap
• An old toothbrush or stiff-bristled grout brush ($5–10)
• Microfiber cloths
• Rubber gloves
• A spray bottle
• Knee pads (you'll thank us)
• For tougher jobs: an oxygen bleach powder (OxiClean or generic), or a commercial grout cleaner
• For the heaviest jobs: a steam cleaner or oscillating tool with grout-cleaning attachment

Method 1: Baking Soda + Water (Lightly Soiled Grout)

The gentlest method. Works for routine maintenance and grout that's just a shade darker than it should be.

1. Mix baking soda with water into a thick paste (about 3 parts baking soda to 1 part water).
2. Spread the paste along the grout lines with your fingers or a small spatula.
3. Let sit 10–15 minutes.
4. Scrub with a toothbrush or grout brush along the line, then across.
5. Wipe clean with a damp microfiber cloth. Rinse and repeat the wipe until no residue remains.

Safe on every type of grout including unsealed.

Method 2: Baking Soda + Vinegar (Moderate Soil)

The fizz lifts gunk out of porous grout mechanically; the mild acid breaks down soap scum and food residue. Don't use on stone tile (marble, travertine, limestone) — vinegar etches calcium-based stone.

1. Sprinkle baking soda directly along the grout lines.
2. Fill a spray bottle with 50/50 white vinegar and water. Spray over the baking soda.
3. Wait until the fizzing stops (about 5–10 minutes).
4. Scrub with a grout brush in small circles.
5. Mop the floor with plain water to rinse fully — leftover vinegar can keep working and slowly degrade unsealed grout over months of repeats.

Method 3: Hydrogen Peroxide + Baking Soda (Heavy Soil, Light Stains)

Peroxide is a mild oxidizing bleach — it whitens organic stains (food, body oils, dye) without the harshness of chlorine bleach. Safe on most colored grout, but spot-test on a small area first.

1. Mix 1/2 cup baking soda with enough 3% hydrogen peroxide to form a paste.
2. Apply along the grout, working in 3x3 ft sections.
3. Let sit 10–15 minutes (longer = stronger, up to 30 minutes max).
4. Scrub with a grout brush.
5. Wipe clean and rinse the floor with plain water.

Skip on dark-colored grout — peroxide can lighten the pigment with prolonged exposure.

Method 4: Oxygen Bleach Soak (Heavy Stains, White or Light Grout)

The breakthrough method for grout that's gone fully brown or gray. Oxygen bleach (OxiClean, generic) is sodium percarbonate — it releases hydrogen peroxide and sodium carbonate in water, deep-cleaning porous surfaces without the harshness or fume risk of chlorine bleach.

1. Mix 2 tablespoons of oxygen bleach powder per 2 cups of warm water in a bucket.
2. Pour directly onto grout lines, OR brush on with a stiff brush. Use enough that the grout stays wet, not just damp.
3. Let sit 15–30 minutes. Re-wet if it dries.
4. Scrub with a grout brush.
5. Mop with plain water until no residue remains — dried sodium carbonate leaves a white film.

Safe on: sealed grout, white and most light-colored grout, ceramic and porcelain tile.
Skip on: dark-colored grout, natural stone, unsealed grout that's recently been recolored.

Method 5: Steam Cleaner or Oscillating Tool (Worst-Case Grout)

The mechanical option for grout that hasn't been cleaned in years and absorbed every spill the floor has ever seen.

Steam cleaner

A handheld or floor steam cleaner with a small detail nozzle ($60–150) blasts grout with 200°F+ steam. The heat liquefies grease and lifts particles without chemicals.

1. Run the steamer in slow passes along each grout line. Don't linger — prolonged steam on one spot can soften unsealed grout.
2. Wipe immediately behind the steamer with a microfiber cloth before the lifted debris re-settles.
3. For visible stains that the steam doesn't lift, follow with Method 4.

Oscillating tool with grout brush attachment

The nuclear option. A $40–100 oscillating multi-tool with a small nylon grout brush attachment scrubs faster and harder than any hand-scrubbing. Use sparingly — it removes grout itself if held too long in one spot.

1. Wet the grout with Method 1 paste or Method 4 solution.
2. Run the brush along each line in steady passes, never stationary.
3. Stop the moment the line is clean — if you see brown dust, you've started removing grout.

What Not to Use

• Chlorine bleach (Clorox). Whitens fast but degrades grout over time, weakens the sealer if there is one, and discolors any colored grout. Also: never mix with vinegar or ammonia — toxic gas.
• Acidic cleaners (CLR, muriatic acid) on stone tile. Etches marble, travertine, and limestone permanently.
• Wire brushes. Scratch the tile and gouge the grout. Always nylon-bristled brushes.
• Pressure washers indoors. Yes, people do this. It blows water under tiles, soaks subfloor, and destroys grout joints. Don't.

Re-Sealing Grout After Cleaning

Cleaning grout is half the job. The other half — the part that determines whether you'll clean it again in a year or a month — is sealing.

How to seal

1. Let the grout fully dry after cleaning. At least 24 hours; 48 in humid conditions.
2. Buy a penetrating sealer (silicone or fluoropolymer-based), not a topical one. $20–40 a bottle, covers 200–500 sq ft. Brands: Aqua Mix, Miracle Sealants 511, StoneTech.
3. Apply with the sealer's applicator brush, a small foam brush, or a rolling applicator. Work in 3x3 ft sections.
4. Wipe excess off the tile face immediately with a microfiber cloth. Sealer dried on tile is hard to remove later.
5. Apply a second coat after 1–2 hours.
6. Let cure 24 hours before walking on it; 72 hours before using a wet room.

How long does sealer last?

• Standard penetrating sealer: 1–3 years on floors, 3–5 on walls.
• Premium fluoropolymer sealer: 5–10 years.
• Heavy-traffic areas: re-seal every 12 months.

Test annually with the water-bead test from the top of this guide. When it stops beading, re-seal.

How to Keep Grout Clean (Maintenance)

• Sweep or vacuum daily. Grit is what grinds into the grout pores over weeks.
• Use a pH-neutral floor cleaner. Anything acidic or alkaline strips sealer faster. Murphy Oil Soap, Method Squirt + Mop, or a generic neutral tile cleaner.
• Wipe up spills immediately. Wine, coffee, oil — these set into porous grout in minutes.
• Steam-mop monthly (sealed grout only). Sanitizes without chemicals and prevents biofilm.
• Reseal on schedule. The cheapest hour of maintenance you can do.

When to Re-Grout Instead of Re-Clean

Some grout can't be saved — replace it instead. Signs:

• Crumbling or missing chunks. Once grout is breaking out of joints, water is getting to the substrate. Re-grout immediately.
• Deep cracks running along the line. Substrate movement — the new grout will crack again unless you fix the root cause.
• Permanent black mold inside the grout itself (not just on the surface). Mold has rooted in; cleaning kills the surface but it returns within weeks.
• Five-year-old grout in a heavy-use bathroom or kitchen. Even with maintenance, grout reaches end-of-life. New grout + new sealer is a half-day job and resets the clock.

Re-grouting a small bathroom floor: ~$30–50 in materials, 4–6 hours of work. A pro charges $400–1,000 for the same job.

Common Mistakes

1. Using bleach as the default cleaner. Damages grout over months, even if it looks great the first time.
2. Skipping the rinse. Residue from any cleaner attracts more dirt and accelerates re-soiling.
3. Not testing on a small area first. Especially with peroxide, oxygen bleach, or acidic cleaners on colored grout.
4. Cleaning, then never sealing. Unsealed grout re-stains in weeks. The seal is what makes the work last.
5. Sealing dirty grout. Seals the dirt in permanently. Always clean first.
6. Using the same dirty rinse water across the whole floor. You're just spreading soiled water around. Change the water every 100 sq ft.

Frequently Asked Questions

What is the best homemade grout cleaner?

Baking soda and hydrogen peroxide paste — it's the closest to commercial oxygen-bleach products and uses only what's in most homes already. Skip the bleach recipes; the long-term grout damage outweighs the short-term whitening.

How long does it take to clean grout on a tile floor?

A 50 sq ft kitchen floor: 1–2 hours for a full deep clean. A whole bathroom: 2–3 hours. The work is mostly in the scrubbing — a grout brush attachment for an oscillating tool cuts the time roughly in half.

Will vinegar damage my grout?

Sealed grout: minor risk only with prolonged or repeated exposure. Unsealed grout: yes, vinegar erodes it over time. Stone tile: vinegar etches the tile itself. Use it sparingly, rinse fully.

Why does my grout look gray when it's supposed to be white?

Embedded dirt that's bonded with old sealer or with calcium deposits. Method 4 (oxygen bleach soak) typically restores it. If it doesn't, the grout has been gray for so long that the dirt is in the pores below the sealer — your only real fix is to grind out and re-grout the lines, or to color-seal it (a tinted sealer applied like paint to the grout lines).

Can I paint grout to make it look new?

Yes — "grout paint" or "grout colorant" (Polyblend, Aqua Mix Grout Colorant) is a tinted sealer you brush directly onto cleaned grout. Lasts 5–10 years. Works only on cement grout, not epoxy. Best for white grout that's gone gray and won't come back.

How often should I deep-clean grout?

Sealed grout in a normal household: once a year. Heavy-use bathrooms or kitchens with cooking grease: every 4–6 months. Unsealed grout: as needed (which will be a lot — seal it).

Is steam cleaning safe for all grout?

Yes for sealed grout. Use cautiously on unsealed grout — prolonged steam on one spot can soften and erode the surface. Don't steam-clean natural stone tile; the heat and moisture can damage the stone.

Clean Once, Seal Once, Forget About It

The reason most people are cleaning grout every few months isn't that they're cleaning wrong — it's that they're not sealing after. Do the full clean-and-seal cycle once, and you'll have clean grout for a year or more. Maintenance becomes a sweep and a damp mop, not a Sunday afternoon on your knees with a toothbrush.

Need supplies? Browse our cleaning supplies for grout brushes, sealers, and pH-neutral tile cleaners — most items ship within 48 hours.