The mold is a microorganism. In order to grow and grow he needs the following living conditions:
In addition, he must be given a nutrient medium. These are food, clothing or other substances, but also the building fabric. So can the wallpaper paste be affected, but also the plaster, paint, wood, earth, carpets and even some types of plastic. Ordinary house dust is enough to cause mold.
The actual mold can not be recognized by the eye. What we see are the spores and fungal threads that are spreading. First, some stains appear, which usually spread out in a circle and then, if not treated, grow into a mushroom carpet.