How to Clean Floor Tile Grout

Grout lines are the first thing to show dirt on a tile floor. That porous, cementitious material between your tiles absorbs spills, foot traffic grime, and mold like a sponge. Even sealed grout eventually discolors. Here are five proven methods to clean floor tile grout, ranked from gentlest to most aggressive—start with the first and work your way down if needed.

Method 1: Baking Soda and Water Paste

Best for: Light discoloration and routine cleaning

What you need:

• Baking soda
• Warm water
• Stiff-bristle grout brush or old toothbrush
• Spray bottle

Steps:

• Mix baking soda and water into a thick paste (about 3:1 ratio).
• Apply the paste directly onto the grout lines using your fingers or a small spatula.
• Let it sit for 10–15 minutes.
• Scrub the grout lines with a stiff brush using small circular motions.
• Spray warm water to rinse, then mop up the residue.

This is the safest starting point. Baking soda is mildly abrasive and alkaline, which helps lift surface grime without damaging the grout or tile. It works well for grout that’s lightly dingy but not deeply stained.

Method 2: Baking Soda and Vinegar

Best for: Moderate grime and light mildew

What you need:

• Baking soda
• White distilled vinegar
• Spray bottle
• Grout brush

Steps:

• Apply the baking soda paste to grout lines as described above.
• Fill a spray bottle with undiluted white vinegar.
• Spray the vinegar over the baking soda paste. It will fizz on contact.
• Let the fizzing reaction work for 5–10 minutes.
• Scrub with a grout brush.
• Rinse thoroughly with clean water and mop dry.

Important note: Don’t use vinegar on natural stone tiles (marble, travertine, limestone, slate). The acid etches and dulls the stone surface. For natural stone floors, stick with baking soda paste only or use a pH-neutral stone cleaner.

Method 3: Hydrogen Peroxide

Best for: Stained grout, mold, and mildew

What you need:

• 3% hydrogen peroxide (standard drugstore concentration)
• Baking soda (optional, for extra cleaning power)
• Spray bottle
• Grout brush

Steps:

• Pour hydrogen peroxide into a spray bottle. For stubborn stains, mix it with baking soda to form a paste.
• Apply generously to the grout lines.
• Let it sit for 15–30 minutes. For heavy mold, leave it for up to an hour.
• Scrub and rinse.

Hydrogen peroxide is a mild bleaching agent and disinfectant. It’s particularly effective against mold and mildew stains in bathrooms and entryways. It breaks down into water and oxygen, so it’s safe for most tile types. Avoid using it on colored grout—it can lighten the pigment.

Method 4: Commercial Grout Cleaners

Best for: Heavy staining and deep-set grime

When DIY solutions aren’t cutting it, commercial grout cleaners use stronger surfactants and acids to dissolve embedded dirt.

Top products:

• Zep Grout Cleaner and Brightener: Acid-based, very effective on white grout. Apply, wait 3 minutes, scrub, rinse. Around $8–$12 per bottle. Not for natural stone or colored grout.
• Black Diamond Grout Cleaner: Alkaline formula safe for colored grout and natural stone. Spray on, wait 1–3 minutes, scrub. Around $10–$15.
• Aqua Mix Grout Deep Clean: Professional-grade, pH-neutral option. Works on all tile and grout types. Around $15–$20.

Safety precautions: Wear rubber gloves with any commercial cleaner. Ensure ventilation—open windows or run a fan. Never mix commercial cleaners with bleach or each other. Test in an inconspicuous area first.

Method 5: Steam Cleaning

Best for: Chemical-free deep cleaning, large floor areas

What you need:

• A handheld or canister steam cleaner with a grout brush attachment

Steps:

• Fill the steam cleaner’s reservoir and let it heat up (usually 5–10 minutes).
• Attach the small grout brush nozzle.
• Hold the nozzle directly on the grout line and move slowly—about 1 inch per second.
• Wipe up the loosened grime with a microfiber cloth or mop as you go.

Steam reaches 200°F+, which kills mold, bacteria, and dissolves grease without any chemicals. It’s the best method for large floor areas because you’re not applying and rinsing products across the entire floor. A decent handheld steam cleaner costs $40–$80. Canister models with more attachments run $100–$200.

Steam cleaning won’t remove deep stains that have penetrated the grout—for that, you’ll still need a chemical treatment first. But for regular maintenance, steam is unbeatable.

What About Oxygen Bleach (OxiClean)?

Oxygen bleach is a solid middle ground between DIY solutions and harsh commercial cleaners. Dissolve 2–4 tablespoons of oxygen bleach powder in a gallon of warm water, pour it over the grout lines, and let it soak for 15–30 minutes. Scrub, then rinse.

Oxygen bleach is color-safe (won’t lighten colored grout), safe for natural stone, and effective against organic stains. It’s the best option when you have colored grout and need something stronger than baking soda.

Tools That Make Grout Cleaning Easier

• Electric grout brush: Battery-powered rotary brushes (like the Rubbermaid Reveal) spin at high RPMs and save your knees and arms. $20–$40.
• Grout brush with long handle: Stand-up grout brushes let you scrub without kneeling. Look for ones with stiff nylon bristles. $10–$20.
• Knee pads: If you’re scrubbing by hand on a large floor, gel-core knee pads are essential. $15–$30.
• Drill brush attachment: A nylon bristle brush that chucks into a cordless drill. Fast and effective. $8–$15 for a set.

Avoid using metal brushes or wire bristle tools on grout. They scratch tile surfaces and can damage the grout itself, creating more pores for dirt to settle into.

How to Prevent Grout from Getting Dirty

Seal Your Grout

Grout sealer fills the pores in cementitious grout, creating a barrier against moisture and stains. New grout should be sealed after it cures (usually 48–72 hours after installation). Reapply sealer every 1–2 years depending on foot traffic.

Two types of sealers exist:

• Penetrating sealers: Absorb into the grout and protect from within. Don’t change the appearance. Best for most residential floors. $15–$30 per bottle (covers 200–500 sq ft).
• Topical sealers: Sit on the surface and create a visible coating. Can add a slight sheen. More prone to wear and peeling in high-traffic areas.

Use Epoxy Grout for New Installations

If you’re installing new tile, consider epoxy grout instead of standard cement grout. Epoxy grout is non-porous, stain-proof, and never needs sealing. It costs more ($5–$8 per pound vs. $1–$2 for cement grout) and is harder to work with during installation, but it stays clean permanently.

Regular Maintenance Routine

• Sweep or vacuum tile floors 2–3 times per week to prevent grit from grinding into grout lines.
• Mop weekly with a pH-neutral tile cleaner (avoid bleach and vinegar for routine cleaning).
• Wipe up spills immediately—especially coffee, wine, tomato sauce, and grease.
• Deep clean grout lines every 3–6 months using one of the methods above.

When to Call a Professional

Professional tile and grout cleaning services use truck-mounted hot water extraction equipment and commercial-grade solutions. They can clean an average kitchen or bathroom floor in 1–2 hours at a cost of $1–$3 per square foot (typical range: $150–$500 for a bathroom or kitchen).

Consider professional cleaning when:

• DIY methods haven’t restored the grout color
• Mold has penetrated deep into the grout and keeps returning
• You have a large floor area (entire first floor, for example)
• The grout is cracked or crumbling (they can regrout after cleaning)

If your grout is permanently discolored and cleaning doesn’t help, grout colorant (also called grout stain) is a last resort before regrouting. Products like Polyblend Grout Renew apply like paint over existing grout and cost $15–$25 per bottle. They work, but they’re tedious to apply—expect to spend 2–4 hours on a typical bathroom floor.