How soon can I walk on the tiled floor after the grout is sealed?

Usually it takes around 30 minutes for a clear penetrating sealer to soak into the grout joints and dry.  Colored grout sealers dry a lot quicker and may be stepped on approximately 20 minutes after installation.   Once the sealer is dry, the floors are ready to be used again as normal.  Both types of sealer require 48 hours to fully cure and harden, during this time the grout lines should not be exposed to any liquids.