Dirty grout makes clean tile look dirty. You can mop a floor perfectly and it will still look dingy if the lines between the tiles have turned gray or brown. If you just worked through How to Deep Clean a Bathroom Like a Pro, grout is likely the one spot you noticed didn't come all the way back. Here's how to fix that.
Why grout gets so dirty
Most grout is porous. It's basically a cement mix, and it absorbs water, soap, body oils and dirt. In showers, soap scum and minerals settle into it. On floors, mop water pushes dirt into the lines and leaves it there. Here in North Texas, red-clay mud tracked in from the yard is especially good at staining light grout, and it gets worse every time a rainy week rolls through.
The result is grout that's darker than it started, and sometimes uneven, with dark patches near doorways, sinks and the shower drain.
Start with the gentlest method
Always start mild and work up. Many grout lines come back with nothing more than hot water and a stiff brush.
- Sweep or vacuum the floor first so you aren't scrubbing grit into the grout.
- Wet the grout with hot water.
- Scrub along the line with a stiff nylon grout brush or a toothbrush, not a wire brush.
- Wipe away the dirty water with a damp cloth before it dries back in.
If that does it, you're done. If not, move to the next step.
Baking soda paste for most stains
Mix baking soda with water into a thick paste. Spread it along the grout lines with your finger or the brush and let it sit for ten minutes or so. Then scrub along the lines and rinse well. For extra power, spritz a little white vinegar over the paste right before scrubbing. It fizzes and helps lift the dirt.
Vinegar is fine for most ceramic and porcelain tile, but skip it on natural stone like marble, travertine or limestone. The acid can etch the stone and leave dull spots that don't come back.
Work in small sections, about an arm's length at a time, so the paste doesn't dry before you scrub it. On a big kitchen or living room floor, a kneeling pad saves your knees, and a small bucket of clean rinse water beside you keeps you from walking back and forth to the sink. It's slow going, but you'll see the difference line by line, which keeps you motivated.
Oxygen bleach for deeper stains
If the paste doesn't get it, try an oxygen bleach powder mixed with warm water according to the label. Oxygen bleach is gentler on grout color than chlorine bleach, and it works well on the gray, dingy look that builds up on floors. Apply it, let it sit for the time the label recommends, scrub and rinse thoroughly.
For mildew in the shower, a mildew remover made for bathrooms is the right tool. Use it with good ventilation and gloves, and never mix it with vinegar or anything with ammonia.
Rinsing matters more than people think. Any cleaner left behind in grout becomes sticky and attracts new dirt. After scrubbing, wipe the area with plain warm water two or three times, using a clean cloth each time. On floors, a final mop with plain water is a good idea.
Seal it once it's clean
Once grout is truly clean and completely dry, which usually means waiting a full day, a penetrating grout sealer helps it resist stains. It doesn't make grout stain-proof, but it buys time and makes regular cleaning easier. Follow the sealer's instructions on how long to wait before walking on it or showering.
Sealing isn't a one-and-done job. Most sealers need to be reapplied every so often, especially in showers and high-traffic areas.
When cleaning isn't enough
Sometimes grout is beyond cleaning. If it's cracked, crumbling, missing in spots or stained deep all the way through, it may need to be repaired or regrouted. Grout color stains and grout pens can also refresh the look of grout that's clean but uneven in color. Those are bigger projects than a deep clean, but they're worth knowing about if you've scrubbed hard and the lines still look tired.
Keeping grout clean
- Use a pH-neutral floor cleaner for regular mopping.
- Change mop water often so you aren't pushing dirty water into the lines.
- Squeegee or wipe shower walls after use.
- Put a mat at every exterior door to catch mud before it reaches the tile.
If you're planning a remodel down the road, ask about darker grout or a stain-resistant grout. Light grout looks beautiful when it's new, but in a busy North Texas kitchen or entry, it takes much more upkeep to keep that way.
Let us scrub the grout
Grout lines are part of our deep cleans, especially in showers and at entry doors. Send us your bedrooms and bathrooms for a free quote.
Get a free quoteWorth the effort
Clean grout makes a whole floor or shower look newer, and it's one of the details people notice right away after a deep clean. It's also slow, kneeling, hands-on work, which is why so many homeowners around the south DFW area hand it off. If that's you, check out our deep cleaning services.