What Causes Mold?
There are a few factors that create the conditions necessary for mold growth.
Your most common being environments that have undesirable levels and/or excess of the following:
However, these issues being fairly common in any average home, the biggest culprit to the development of mold is moisture.
Typical reasons for this being present range from leaks (roof, pipes) and condensation buildup due to poor ventilation. Areas particularly vulnerable are basements and generally damp spots left undisturbed for mold conditions to thrive.