It is common knowledge that mold is everywhere. Fungi, which include mold and mildew, make up more than one-quarter of all life on earth, and some molds contribute significantly to our quality of life.
Recently, there has been increasing interest in the potentially damaging health effects a small number of mold species can have. These effects raise concerns for those involved in the roofing industry because mold increasingly has been found in commercial roof assemblies and can affect indoor air quality. In many cases, the ceiling plenum, which is in contact with a roof assembly, becomes the return air duct for a building.
Occupied buildings with interior moisture sources, such as recreation centers, paper manufacturing and food-processing plants, multifamily buildings and schools, can generate water vapor, which must dissipate or be ventilated so it does not accumulate and become a mold source.