How to Clean Grout (Floors & Tile)

Figuring out how to clean grout brings tile floors and walls back to life more than almost any other cleaning task, because the dingy grid of lines between tiles is usually what makes a room look dated. Grout is porous cement, so it soaks up dirt, soap scum, and grease over time and darkens. The good news is that most discoloration is surface grime, not permanent staining, and it lifts with a mild cleaner, a stiff brush, and a little patience — no harsh chemicals required for everyday cleaning.

What is the best thing to clean grout with?

Start with the gentlest cleaner that works and only escalate if you must, because strong acids and bleach can erode or discolor grout and damage natural stone. For routine dirt, warm water and a stiff nylon brush remove a surprising amount. For greasy or soap-scummed lines, a paste of baking soda and water scrubbed in and rinsed clean handles most of it. Save oxygen bleach (not chlorine) for stubborn gray film, and reserve stronger products for the rare genuinely stained line.

Which cleaner suits which surface?

The tile material decides what is safe, so check this before you reach for anything acidic.

What tools make grout cleaning easier?

You do not need much, but the right few items turn a miserable job into a manageable one. A stiff nylon grout brush with a narrow head reaches into the lines far better than a flat scrub brush, and an old toothbrush handles corners and edges. Keep a spray bottle for your cleaner, a couple of microfiber cloths for rinsing, a bucket of clean water, and knee pads if you are doing a floor. Skip metal or wire brushes entirely — they gouge the grout and leave it rougher, so it traps dirt faster afterward. A grout saw and a tube of fresh grout are worth having on hand only if you discover crumbling lines that need replacing rather than cleaning.

How to clean grout, step by step

Whether you are working on a floor or a tiled wall, the sequence is the same: dry sweep, apply cleaner, dwell, scrub, and rinse.

How do you prepare the area?

Sweep or vacuum floor tile first so you are not grinding loose grit into the grout, and wipe walls down with plain water to clear surface dust. Ventilate the room and put on gloves. Working on clean, dry grout lets the cleaner reach the grime instead of mixing with loose dirt, which is why this quick step makes the scrubbing far more effective.

How do you apply and scrub the cleaner?

Spread your chosen cleaner along the grout lines, not the whole tile, and let it dwell for five to ten minutes so it can loosen the grime — do not let it dry out. Then scrub along each line with a stiff nylon grout brush or an old toothbrush for tight corners, using short back-and-forth strokes. Let the brush and cleaner do the work rather than your shoulders; grout responds to dwell time more than brute force. Rinse frequently with clean water and a cloth so you are lifting the dirt away instead of pushing it around.

Safety note: never mix bleach with vinegar, ammonia, or other cleaners, keep the room ventilated, and test any new cleaner on a hidden patch of grout first, especially around natural stone.

How do you handle stubborn stained grout?

For lines that stay gray after a normal scrub, mix oxygen bleach powder with warm water into a loose paste, spread it over the grout, and let it sit for fifteen to thirty minutes before scrubbing and rinsing. A steam cleaner is another chemical-free option that lifts deep grime with heat; run the nozzle slowly along each line so the steam has time to work, then wipe the loosened dirt away. If a few lines remain permanently discolored even after that, a grout pen or a re-coloring product coats the grout in a fresh, uniform color and doubles as a sealer, which is far cheaper than regrouting. Badly cracked or crumbling grout, on the other hand, should be raked out with a grout saw and replaced rather than cleaned, since cleaning cannot restore grout that has failed.

Is it dirt, or is it mold and mildew?

In showers and other damp spots, dark grout is often mildew rather than ground-in dirt, and the distinction changes your approach. Mildew tends to look spotty, black or pink, and appears where water lingers; it will keep coming back until you address the moisture, not just the surface. An oxygen bleach paste or a dedicated mildew remover clears it, but ventilation and drying the area afterward are what keep it gone. If the grout is cracked or the dark staining is actually under a clear-silicone caulk line around the tub or sink, cleaning will not reach it — that caulk should be cut out and replaced. Knowing which problem you have saves you from scrubbing the same spot every week.

What are common grout-cleaning mistakes to avoid?

A few habits quietly make grout worse. Using acidic cleaners like vinegar or lemon on cement grout and stone slowly etches them; scrubbing with wire brushes roughens the surface; letting a cleaner dry on the grout can leave its own residue; and cleaning without ever sealing means you are back at square one within weeks. The biggest mistake is impatience — rushing the dwell time and then scrubbing twice as hard, which tires you out and still leaves grime behind.

How do you keep grout clean longer?

Sealing is the step most people skip. Once clean grout is fully dry, apply a penetrating grout sealer to cement-based grout and reapply yearly in wet areas; the sealer repels water and dirt so future cleaning is far easier. In the shower, squeegee the walls after use and run the fan to cut the moisture that feeds mildew. While you are maintaining the bathroom, the buildup that dulls grout also clogs fixtures, so our guide on how to clean a showerhead pairs naturally with this job, and if a constant drip is keeping the area damp, fixing it using how to fix a leaky faucet removes the moisture source that keeps grout grimy.

How often should you clean grout?

Wipe shower and backsplash grout weekly with whatever all-purpose spray you already use, scrub floor grout every few weeks in high-traffic areas like kitchens and entryways, and do a deep clean and reseal once or twice a year. Light, frequent cleaning is far easier than a single heroic effort, because grime that never sets in never needs an oxygen bleach soak to remove. Folding these into a routine keeps the lines from ever reaching the dark, set-in stage, and our home maintenance seasonal checklist is a simple way to make sure the deep clean and reseal actually happen on schedule. Clean, sealed grout can make an old tile floor look nearly new, so it is one of the highest-payoff hours you will spend. For more projects like this, visit the full home improvement collection.