What is mold and why is it an issue today?
Mold is ubiquitous in nature. We come in contact with it on a daily basis. There are thousands of species of mold—most of them are harmless—but none of them will grow in the absence of water or moisture. The antibiotic penicillin is derived from mold, as is the brewing of beer. In fact, our ecosystem would not function without mold—mold turns grass, leaves and other yard waste into topsoil.
Mold has become an issue today because it’s more prevalent, particularly in structures built during the past 25 years. The focus on improving energy efficiency resulted in more airtight homes that don’t breathe like older structures. More complex home designs create increased potential for moisture intrusion. In addition, under today’s accelerated building schedules, buildings are subjected to the elements during all phases of construction, which can introduce and trap moisture within a building. It’s important to note, however, that an energy-efficient home is not necessarily susceptible to mold. With proper design and construction, a home can be both energy-efficient and free from moisture-related problems.
What causes mold?
Mold spores waft through the air continually—indoors and out. When mold spores land on a damp spot, they begin digesting whatever they grow on to survive. Three conditions must always be present for mold to grow: 1) mold spores; 2) moisture; and 3) a food source upon which it can feed. Mold can grow on any surface—including steel, plastic and glass. A layer of dust provides enough nutrients to support mold growth. Of the three requirements to grow mold, only moisture can be controlled. Eliminating mold spores and all nutrients would require “clean room” technology, something that cannot be duplicated easily in spaces where we live and work.
Common causes of moisture and mold in buildings once they are completed include:
• Plumbing system leaks
• Air conditioning condensation
• Inadequate or incorrectly installed flashing around doors and windows
• Poor roof design (shallow overhangs or unprotected gable ends)
• Inadequate grading leading to poor site drainage
• Incorrectly installed insulation
• High indoor humidity exacerbated by inadequate ventilation
• Condensation caused by moist air moving in and out of the building envelope
• Large temperature differences
• Leaking ductwork
Can mold cause health problems?
Research on the health effects of mold is ongoing. The general consensus is that mold does not represent a health issue for most people. However, mold does produce allergens, which are substances that can cause an allergic reaction. Allergic responses include hay fever-type symptoms such as sneezing, runny nose, red eyes and skin rash. In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people. It’s important to note, however, that people who are allergic to pollen or even cat dander also experience the same symptoms. Generally, only people with asthma or compromised immune systems are likely to be affected by mold.
Myths about mold
1. Mold grows only on paper, wood and other organic material
Mold will grow on any surface, including glass, fiberglass and even steel. Mold needs three things to grow: 1) mold spores (which are almost always in the air); 2) moisture; and 3) a food source. Houses are constructed using a wide variety of organic materials; therefore, the only effective strategy to control mold is to control moisture.
2. Mold can be eliminated
We all benefit from some molds such as the species that led to the development of penicillin. Only “clean room” technologies—which are too expensive and unnecessary for the home or office—can eliminate mold spores. Therefore, the only thing you can control in your home or office is moisture.
3. Only experts can clean mold
Homeowners can clean small patches of mold using household detergents and warm water. After cleaning, rinsing and drying the spot where mold has grown, rubber gloves and cleaning cloths used in the process should be discarded. Larger patches of mold may need to be eliminated by trained professionals.
4. Once mold starts, it will always be present
Mold can be stopped in its tracks, but only if moisture is minimized or eliminated. Therefore, leaks should be corrected as soon as they become apparent. Building experts urge homeowners to be aware of some of the telltale signs of mold, which include dampness, odors, discoloration, peeling paint, condensation, compacted insulation and actual mold outbreaks.