Contractor left grout on tile for 36 hours and never showed back up. How do I clean this up?! Mr Cheaply On 1:17 AM The tile is porcelain and the grout is sand polyblend grout.I don't want to damage the tile and I don't want the grout to harden into full blown concrete.Pictures:grout Covered Tiles via /r/DIY http://ift.tt/2wcqm77