A custodial worker is responsible for general housekeeping, cleaning, and maintenance within a building. Your job duties include emptying trash receptacles, sanitizing bathroom facilities, mopping floors, vacuuming carpets, and maintaining the overall appearance of the building. The qualifications for a career as a custodial worker include a high school diploma or equivalent GED certification. Some employers may hire individuals without a high school diploma. A successful custodial worker needs a strong work ethic and a excellent attention to detail.