Tile and grout cleaning in Cleveland
Grout is basically a sponge. It soaks up mop water, grease and salt off boots until the lines turn gray. We clean it with hot water under pressure and pull the dirty water straight back up.
Why mopping doesn't fix it
Grout sits a little lower than the tile, so a mop pushes dirty water around and leaves some of it in the lines. Every week they get a little darker. Scrubbing by hand helps, but it's slow, and it's hard on your knees.

How we clean it
We spray a cleaner that suits the tile and let it sit. Then we go over it with a spinning tool that sprays hot water and vacuums at the same time, so the dirt comes up instead of getting pushed into the next line. Natural stone like marble and travertine gets a pH-neutral cleaner, because anything acidic will etch it.
Sealing
Once the grout is clean and dry, sealing it makes it much harder for dirt to get back in. It's optional, but in a kitchen or the entry where everyone kicks off their boots, we'd do it.
What it costs
Figure $0.85 to $1.50 a square foot to clean, plus about $0.50 to $1 a square foot to seal. Most kitchen floors end up between $150 and $350.
Common questions
Will the grout look new?
It'll be a lot lighter. How close it gets to the original color depends on its age and whether it was ever sealed. Grout that's cracked or crumbling needs regrouting, not cleaning.
Do you do showers?
Shower walls and floors, yes. Heavy soap scum and mildew take longer, so we quote them separately.