What's in your walls
Mold becomes a problem inside a home or business when there's a lot of humidity or any kind of moisture for a long period of time. The problem can start with something like a broken pipe or large spill that goes untreated, or from a leaking roof or plumbing. Even high humidity or warm, moist air condensing on cool surfaces can trigger mold problems.
Mold can grow almost anywhere in a home or business. If there is visible growth on painted walls, property owners should be concerned about the mold that could be growing on the other side. The environment inside the walls of a house or business is very different from the outside and makes a perfect home for mold. If the wall remains wet for a prolonged period, it's almost guaranteed that the mold growth on the back side will be worse than on the front. At that point, containing the work space and removing moldy materials, followed by cleaning of salvageable framing, are the best options