Choose a professional who specializes in Grout and Tile repair and restoration. The business of Grout cleaning, repair and restoration is a specialized field. Do not trust a company that treats it as a sideline business. Knowing the many types of tile and grout and which products to use or not use requires training and experience.
Choose a company willing to visit your home or business and do a demonstration of their work, so you know how the finished job will look. Always get a firm written estimate and ask about the completed job warranty.
Choose a company that uses professional products approved by all grout and tile manufacturers. Never use acids, commercial steam cleaning equipment, pressurized water systems or carpet cleaning equipment on your tile and grout. They will damage your floors.