The answer to 'why is my tile mildew' is that tile and grout are prone to mildew growth due to their porous nature and exposure to moisture. Mildew is a type of fungus that thrives in damp, dark environments and can discolor tile and grout, making them appear dirty or stained.
Common causes of tile mildew include excessive moisture from poor ventilation, leaks, or high humidity, as well as lack of regular cleaning and maintenance. Symptoms include a fuzzy, discolored appearance on the tile or grout, and a musty odor. To prevent and remove tile mildew, it's important to address the underlying moisture issue, clean the tile regularly, and use mildew-resistant sealers or grout.