Clean dirty grout without harsh chemicals
White grout gradually turns gray as dirt settles into its surface. A baking soda paste and a stiff brush can lift much of that everyday grime. Once it's clean, sealing it helps keep stains from soaking back in. Skip the wire brush. It gets grout clean fast, but it also scratches the tile and chews up the grout you're trying to save.
Why grout gets dingy
Grout is basically sand and cement, and it's full of tiny pores. Everyday grime settles into them, which is why wiping the surface never quite gets it clean. A mildly gritty paste and a narrow brush that fits the grout line do much better, along with a little patience.
What stains grout
They settle into the grout's pores in showers.
Dark spots in damp corners are usually mildew.
On floors, dirty mop water gets pulled into grout lines.
Unsealed grout absorbs everything.
| Stain | Try this |
|---|---|
| General gray grime | Baking soda paste and a stiff brush |
| Mildew spots | Baking soda with 3% hydrogen peroxide instead of water |
| Soap scum in the shower | A little dish soap in warm water, then rinse well |
| Stains that won't come out, or crumbling grout | Regrout that area |
Scrub, rinse, seal
- Mix a pasteStir baking soda with a little water until it's like toothpaste.
- Spread it on the groutWork in a small area at a time, about 2 by 2 feet. Spread the paste along the lines and mist it lightly.
- Scrub along the lineScrub back and forth along the grout, not across it. Let the brush do the work.
- Rinse and wipeWipe away the paste with a damp cloth, rinsing often, then dry the area.
- Seal once it's fully dryWait 24 hours, or as long as the sealer's label says, then brush it on. Once it cures, a drop of water should bead up on the grout instead of darkening it.
Watch it done
- The grout lines look evenly lighter across the area
- No paste residue left on the tile
- A drop of water beads up on sealed grout instead of darkening it
Stains won't budge? Try 3% hydrogen peroxide with baking soda.
If stains won't come out
If stains won't budge, try 3% hydrogen peroxide mixed with baking soda. For really dark grout, a grout colorant can make it look even again.
Crumbling, cracked or missing grout needs regrouting, not cleaning, or water will get behind the tile.
What a pro typically charges (a rough estimate; prices vary by area): Professional grout cleaning often runs $150–$400 per room. Regrouting a shower typically costs $300–$800.
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