Yesterday, two elves cleaned tile floors for an old customer. About a year ago we were unable to do it due to the timing, so she hired a well known national franchise. My foreman told me that he had a tough time getting the grout to even out in color, until he realised that it has been coated and the anomolies were scraps of coating. He also described how the grout was deeply gouged and in places, missing. We use low pressure, high temp steam to clean and haven't ever blown grout out (unless it was already visibly crumbled. How often does this happen to you pressure washing tile guys? Is is something you disclaim ahead of time? Is there anything I should know as customers ask "how did this happen?" I have a few guesses, but no experience on indoor pressure cleaning.