When my husband Max & I bought our house, all of the tiles, hardwood, & carpet was brand new and clean . The white tiles in the home office had a fresh, wash white grout as well. The home office sparkled when it sat empty, but after residing in the place for multiple years, Max & I began to see the discoloration in the home office. All of the grout was grimy & dirty. Instead of a fresh & clean white color, the grout was a dingy light brown. Max & I contacted a couple of janitorial services & we found a supplier that offered tile floor cleaning services. The tile floor cleaning service was undoubtedly infancy. They charged rates according to the square footage of the part cleaned. Max thought that was adequate, given the fact that some people have greater home offices than others. The janitorial service used state of the art equipment to wash all of the tiles; He sprayed something on the grout as well. After 15 hours, the cleaning expert used pressure washing equipment to wash the tiles & the grout. The equipment used water to clean the floor, but it had a suction system that kept the water in a separate compartment. The tile cleaning guy removed all of the old discoloration from the route, then by the time he was finished, our home office looked brand new. Max & I made an appointment with the same flooring supplier & next week we are going to have them wash out the carpets & substitute some of the old tiles in the upstairs lavatory. The men have torn up that lavatory.