To start with we must have the fungus present. Since mold causing fungi are ubiquitous in most areas, their exclusion is not practical. A susceptible substrate is another requirement. Most buildings are made up to a large extent of wood or paper products and these are for most fungi, acceptable food sources. It is not feasible to do away with susceptible plant based building products. Certain fungi such as the Aspergillus group require a higher energy level from seeds or other energy rich sources. The Cladosporium group will often require energy sources such as dead insects or insect and animal feces. These food sources can be eliminated and consequently the Aspergillus and Cladosporium fungi can be avoided. All fungi require a favorable environment in which to grow. Water and warm temperatures make up this favorable environment. Water is the requirement that can be most easily eliminated and is thus the single most important parameter in the prevention of mold in houses.
