Hydroclean has been developing building restoration cleaning systems for the professional restoration cleaning contractor for over 28 years. Our products are practical, reliable and consistent in the field and, we feel represent the state of the art in high pressure water and chemical cleaning technology. Before and after photos of some granite steps, unpolished marble side walls, marble columns and column capitols, and polished marble columns. Photos of an interior stairway in the Connecticut State Capitol, Hartford, Connecticut.