Ok, i've installed ceramic tile over concrete saturday and done the grout thing monday. It looks really good to me, just wondering if i should do anything to the grout and when it would be save to mop up the excess dust that has collected in the grooves. Its gonna be used for a laundry/mud room.
Spray the grout lines with a grout sealer. I would recommend using the "good" stuff. Follow the directions. Usually they recommend letting the sealer penetrate for around 10 minutes. Then wipe of the excess on the tile, not the grout. Then, and only then will the floor be safe for everyday use.