You mop the floor, it looks great for a day, and the grout lines still look dark. It’s one of the most common complaints we hear about tile, and there’s a simple reason for it.
Why grout gets dirty when tile doesn’t
Tile is hard and smooth. Grout is basically sand and cement, and it’s porous, full of tiny holes that soak up liquid. Every time you mop, dirty water runs off the tile and settles into the grout lines, which sit a little lower than the tile. The water dries and the dirt stays behind. Do that a few hundred times and the grout turns gray or brown.
A mop that isn’t rinsed often makes it worse, because you end up spreading the same dirty water across the whole floor.
Bathrooms have their own problem
In showers and bathrooms, the issue is moisture. Houston humidity means bathrooms take longer to dry out, and grout that stays damp is a good place for mildew to start. Those dark spots in shower corners usually aren’t dirt at all.
What you can try yourself
- Start gentle. Make a paste of baking soda and water, work it into the grout with a stiff nylon brush (an old toothbrush works for small areas), let it sit a few minutes, then scrub and rinse.
- Use a cleaner made for grout. Read the label and make sure it’s safe for your tile.
- Rinse well and dry the floor. Leftover cleaner attracts dirt.
A few things to avoid:
- Acids on natural stone. Vinegar and acidic cleaners can etch marble, travertine and limestone. If your tile is natural stone, only use products labeled safe for it.
- Bleach on colored grout. It can leave blotchy, faded patches.
- Wire brushes. They scratch tile and chew up grout.
- Mixing cleaners. Never mix bleach with ammonia or acidic products. The fumes are dangerous.
Seal it once it’s clean
Sealing grout doesn’t make it waterproof, but it slows down how fast spills and dirty mop water soak in. Seal only after the grout is completely clean and dry, otherwise you’re sealing the dirt in. Follow the sealer’s directions for how often to reapply, since products vary. Showers and kitchen floors usually need it more often than a guest bathroom.
Keeping it clean longer
- Sweep or vacuum before mopping so you’re not turning dust into mud.
- Change mop water often, and rinse the mop as you go.
- Use a pH-neutral floor cleaner for routine mopping.
- Run the bathroom fan during and after showers, and squeegee the walls if you can.
- Wipe up spills, especially coffee, wine and sauces, before they soak in.
When to call a professional
If the grout is still dark after a good scrub, the dirt has worked deep into it and household methods won’t reach it. Large floors are also a lot of hands-and-knees work. A professional cleaning can bring grout back much closer to its original color, and it’s a good time to seal it afterward.
Key Cleaning and Restoration Services has been helping Houston-area homeowners since 2002. Learn more about our tile and grout cleaning service, call (713) 570-6282 Monday through Friday, 8 AM to 6 PM, or request a quote online.