If you ever have your house mold tested, don’t be surprised when you find out it passes inspection with a high mold content in the air. You think you’d be aiming for zero mold spores, right? Wrong. There are so many spores in the air that the target value is not zero; it is just lower than the spore content in outdoor air.
The spores are there, floating around in the air and when they land on surfaces, you’d better home those surfaces are dry, because if they’re wet, that spore is going to plant itself and make itself right at home.
So the first line of defense in the battle against mold is not to let it start. Take care of that excess moisture, leaky roof, and leaky pipes or mold will be there to haunt you.