Mold is a microscopic organism that is neither plant nor animal and is everywhere. Mold is a type of fungus that grows in moist soils, dark places that are relatively warm and have an adequate supply of food. Although some molds cause disease or food spoilage, others are useful in the production of antibiotics (penicillin) and preparation of food (cheese, soy sauce, etc). Molde (also called mold) can live both indoors and outdoors and is a common component of household dust. When mold spores are present in sufficient quantities, may present a health hazard to humans and animals.

In buildings under certain environmental conditions can promote mold growth. Since the 1970s new construction techniques were adopted in an effort to conserve energy. The idea was to make buildings sealed to prevent heat loss thus reducing energy consumption. This, combined with new porous building materials such as drywall, greatly reduced the air flow condition, means any accumulation of moisture due to normal human activities could result in mold growth.

Mold is a problem for several reasons. First, has the potential to destroy the surface on which it grows. But above all, molds can produce mycotoxins, which can be harmful or lethal to humans and animals if they are exposed to a high enough. The most common health problems associated with mold include, among other things: allergic reactions, asthma attacks, eye irritation, nose, throat and sinus infections and congestion.

Mold can grow on almost any surface exposed to moisture. When molds reproduce, create spores that can be in the air and carried across. If these spores move to land in a moist environment, which in turn begin to grow. The source of moisture can vary from a leak somewhere hidden in a wall or ceiling in the house, a high general level of moisture in the air due to poorly ventilated spaces, or improper construction practices, provides no protection from rain or snow or not allowing sufficient drying time before closing up. Sometimes, after a single incidence of water infiltration as a flood, mold spores will remain dormant until reactivated after the introduction of appropriate conditions.

Serious mold problems can be identified simply with a mold test kit. A high reading would indicate a problem that warrant further investigation. If mildew becomes a problem, the first step would be to identify and eliminate sources of moisture. The second and decisive step would be the removal of the mold itself. In the process, building materials that are contaminated or wet, they would be discarded. The most common practices for mold remediation include the use of ultraviolet light, as exposure to sunlight, providing adequate ventilation, the installation of porous building materials as much as possible and regularly disinfecting cleaners appropriate any corners poorly lit and poorly ventilated area.