Maintaining multi-story buildings clean and safe over time requires regular maintenance. Common areas like hallways and staircases should be inspected regularly for mold growth, dirt and debris. Pay attention to damp spots, which can attract mold growth. It is possible to keep your multi-story building clean by checking for dirt and other debris. You may find cobwebs in areas that are difficult to reach such as behind furniture and corners. You may also find dirt on walls, stairs, and walkways. Before you move on to the deep cleaning, clean any dirt or debris using a vacuum, brush, or other tools.