How to Clean Grout (and When to Call a Pro)

To clean grout, sweep or vacuum first, apply an alkaline or pH-neutral cleaner, let it sit a few minutes, scrub the grout lines with a stiff nylon brush, then rinse and pick up the dirty water instead of letting it dry back into the joints. The Tile Council of North America calls cleaning, extracting and rinsing "the absolutely best way to clean grout." Skip vinegar and acids on cement grout and natural stone.

Grout gets dark for a simple reason. Most of it is cement, and cement is porous, so it soaks up mop water, grease and soap. Our crews scrub kitchen floors, shower walls and restroom tile across Warren and Youngstown every week, and the method below is the same order we follow, scaled down for a homeowner with a bucket and a brush. If you would rather hand it off, see our tile and grout cleaning service.

What Kind of Grout and Tile Do You Have?

Most homes have cement-based grout, which the Tile Council of North America (TCNA) describes as porous enough to absorb a stain. Epoxy grout is nearly as stain resistant as the tile itself. The tile matters just as much: ceramic and porcelain handle stronger cleaners, while marble, limestone and travertine react to any acid.

You can usually tell the grout type by feel and age. Cement grout looks sandy or matte and darkens when wet. Epoxy grout looks slightly glossy, feels almost plastic and was most likely put in on purpose by an installer, often in a newer shower or a commercial kitchen. If you are not sure, treat it as cement grout. That is the more fragile choice, so the safe method still works.

The Natural Stone Institute is direct about the stone row: "Products containing lemon, vinegar or other acids may dull or etch calcareous stones," and scouring powders "may scratch certain stones." It also warns that some rust removers contain hydrofluoric acid, which attacks every type of stone, granite included.

What Is the Best Thing to Clean Grout With?

The best grout cleaner for most homes is an alkaline tile and grout cleaner or a pH-neutral cleaner, used with a stiff nylon brush. TCNA says alkaline cleaners are preferred over acids, because acids dissolve the cement in grout. For light dirt, a paste of baking soda and water is a gentle, cheap alternative on ceramic and porcelain.

Grout sealer makers say the same thing about upkeep. LATICRETE's data sheet for its STONETECH Heavy Duty Grout Sealer says highly alkaline, acidic, ammoniated or abrasive cleaners are not needed for daily maintenance and can wear down the sealer. It recommends a neutral pH cleaner for routine cleaning and a stronger cleaner with a nylon pad or stiff brush only for tough soil.

Avoid oil soaps and wax-based floor cleaners on tile. TCNA notes they leave a film that attracts dirt, and soap left on the floor does the same. That film is why a floor can look fine wet and gray again two days later.

Here is what we see on almost every first visit: the grout is not dirty because nobody cleans it. It is dirty because it gets mopped often with a cleaner that never gets rinsed. Each mopping leaves a thin layer of soap and dirty water in the joints. Using less product and rinsing with clean water fixes more grout than any stronger chemical does.

How to Clean Grout, Step by Step

This is the method TCNA calls the best way to clean grout, adapted for a home without a truck-mounted extractor. Plan on about 30 to 60 minutes for a small bathroom floor. Work in sections of about 3 by 3 feet so the cleaner never dries on the floor before you rinse it.

1. Remove loose dirt. Sweep and vacuum the floor, including the edges. Grit left on the floor turns to mud the moment it gets wet and packs into the grout lines.
2. Test a small spot. Try your cleaner in a corner or behind the toilet first, especially on colored grout or any stone tile. Check for fading or dull spots after it dries.
3. Apply the cleaner. Spray or brush the cleaner onto the grout lines, mixed exactly as the label says. Let it sit for the dwell time on the label, usually a few minutes. Do not let it dry.
4. Scrub the joints. Use a stiff nylon grout brush along each line, then across it. A narrow brush gets into the joint better than a sponge. Never use a wire brush on glazed tile.
5. Pick up the dirty water. This is the step most people skip. Use a wet/dry vacuum, a squeegee and towels, or a sponge you wring out into a separate bucket. The goal is to get the dirt off the floor, not spread it.
6. Rinse with clean water. Wipe or mop with plain water and pick it up again. TCNA says leftover soap film is one of the most common reasons grout gets dirty again fast.
7. Dry and check. Let the floor dry fully, then look at it in daylight. Spots that are still dark may need a second pass or a stronger alkaline cleaner.

Here is a quick supply list for the job:

• Stiff nylon grout brush (not wire)
• Alkaline or pH-neutral tile and grout cleaner
• Baking soda for a paste on light stains
• Two buckets: one for cleaner, one for wringing dirty water
• Wet/dry vacuum or squeegee and old towels
• Rubber gloves and eye protection
• A fan or open window for ventilation

Can You Clean Grout With Vinegar or Bleach?

Vinegar is a poor choice for grout. It is an acid, and TCNA says acids dissolve the cement in grout and can strip some of its color, while the Natural Stone Institute says vinegar can etch marble, limestone and travertine. Bleach can lighten mildew stains on ceramic tile, but it should only ever be used alone, rinsed well and with fresh air.

The bigger danger is mixing. In its "Mixing Bleach with Other Cleaning Products Can Be Deadly" hazard alert, the New Jersey Department of Health explains that bleach mixed with ammonia creates chloramine gases, and bleach mixed with an acid releases chlorine gas. Even low levels can cause coughing and breathing problems, and very high levels can be fatal.

The same alert lists vinegar, lemon juice, toilet bowl cleaners, rust removers and some drain cleaners as products that react with bleach. It also warns that hydrogen peroxide mixed with vinegar forms peracetic acid, which irritates eyes, skin and lungs. That rules out a lot of the "magic grout paste" recipes passed around online.

The risky moment is not usually mixing two bottles on purpose. It is spraying bleach on shower grout that still has an acid soap scum remover or toilet cleaner on it from earlier in the day. Our rule on every job is one product per surface, rinse it off completely, then move to the next one. Do the same at home and you avoid the problem entirely.

How Do You Get Mold Out of Shower Grout?

For mold on tile and grout, the EPA says to "scrub mold off hard surfaces with detergent and water, and dry completely." If the moldy area is smaller than about 10 square feet, the EPA says you can usually handle it yourself. Running a fan or opening a window and cleaning more often helps keep it from coming back.

Shower grout is the hardest grout in the house to keep clean because it is wet every day. The EPA notes that places that are often or always damp can be hard to keep completely free of mold. Squeegee the walls after showers, run the exhaust fan for a while afterward and wash the grout on a regular schedule. If dark spots come back within days of a good scrub, the mold may be growing behind cracked grout or failed caulk, which cleaning cannot reach.

Should You Seal Grout, and How Often?

Yes, seal cement grout after a deep clean. TCNA calls sealing a very good idea for cement grout and says epoxy grout does not need it. LATICRETE rates its STONETECH grout sealers for up to 5 years of wear on indoor surfaces and up to 3 years outdoors, and recommends reapplying its Stone, Tile and Grout Sealer annually for best results.

Timing matters. Grout has to be clean and fully dry before sealer goes on, or you seal the dirt in. For brand new grout, Custom Building Products' TileLab Grout Sealer data sheet says to let the grout cure 48 to 72 hours, and LATICRETE's sealer sheets say to wait at least 72 hours. TCNA adds that penetrating sealers last longer than topical ones, which wear off under foot traffic.

Those intervals are our working schedule, not a manufacturer rule. The easy way to check is a water drop test. Put a few drops of water on the grout. If they bead up, the sealer is still working. If the grout darkens and soaks them in within a minute or two, it is time to clean and reseal.

When Should You Call a Pro to Clean or Regrout?

Call a pro when the grout is still dark after two careful cleanings, when you have a large area or a natural stone floor, or when the grout is cracked, crumbling or missing. Cleaning fixes dirt. It cannot fix grout that has failed, and TCNA says joints "cannot be grouted over" successfully.

• Grout stays gray, brown or black after two full cleanings
• Cracks, crumbling or gaps along grout lines
• Loose or hollow-sounding tiles near the bad grout
• Mold that returns within days of scrubbing
• Etched or dull spots on marble or travertine from old acid cleaners
• A whole kitchen, basement or commercial restroom to do, not one small bathroom

Cracked or crumbling grout usually means regrouting, and that is a bigger job. TCNA says at least two thirds of the old grout's depth has to come out before new grout goes in, and that cracking often traces back to movement in the floor below. HomeAdvisor's 2026 cost guide puts regrouting at $10 to $25 per square foot, with an average shower regrout around $1,500. That is why it pays to clean and seal before grout gets that far.

A tip from the field: before you assume grout is ruined, look at the grout behind the toilet or under the edge of a rug. Those spots get less traffic and mopping. If that grout is lighter, the rest is just dirty and will clean up. If it is the same dark color everywhere, the grout may have been stained or colored that way, and a pro can tell you which before you spend money on regrouting.

How Phillips Care Cleans Tile and Grout

Our crews follow the same order you just read, with commercial tools. We identify the tile, test a spot, pre-treat, scrub the grout lines by hand and by machine, then rinse with hot water and extract so the dirt leaves the building. Sealing is available at the end of the same visit. Stone gets stone-safe products only.

We clean tile in kitchens, showers, entries and commercial restrooms across Trumbull and Mahoning County, and tile and grout work pairs well with house cleaning or a full move-out cleaning, where clean grout helps a rental pass inspection. Working through the whole house? Our deep cleaning checklist covers every room, and our guide to carpet cleaning cost in Warren explains pricing for the carpeted rooms. Fernando Phillips founded the company in Warren in 2012, and we are insured and bonded. Call (330) 219-7916 or book a free walk-through on our tile and grout cleaning page.