As a high school janitor, your responsibilities include keeping the building clean and operational through various means. Picking up trash, performing maintenance on smaller facility items, and cleaning each room of the building are regular duties in this position. You are responsible for maintaining facilities both inside and outside the school. While you might fix toilets or clean spills inside, your outside duties might consist of pressure washing walkways or landscaping. However, some schools with a large campus may have separate janitors and groundskeepers. A high school janitor is a jack of all trades, so you need skills and know-how in a variety of areas.