Mold can grow on windows for a variety of reasons, but the most common cause is high humidity and moisture.
Here are a few reasons why mold might grow on windows:
Condensation: When warm, humid air comes into contact with a cold surface, such as a window, it can cause condensation to form. This condensation can provide a perfect environment for mold to grow.
Poor ventilation: If a room has poor ventilation, the humidity level can become high, which can lead to mold growth on windows and other surfaces.
Leaky windows: If a window is not properly sealed or has a leak, water can enter the window frame and create a breeding ground for mold.
Poor drainage: If water is not properly drained away from a window, it can lead to mold growth on the window frame or sill.
High humidity: High humidity in general can cause mold to grow on windows, especially in the bathroom and kitchen where there is more moisture.
It's important to address the underlying cause of the mold growth on windows and to clean and remove the mold promptly to prevent it from spreading and causing health issues. It's also important to use proper ventilation and dehumidify the room, or to address any leakage or poor drainage issues, to prevent the mold from returning.