Taming the Mold Monster

Conditions that lead to mold can affect buildings and structures as well as whatever is contained within them.

In the case of records storage centers, that means the same conditions that cause structural wood and walls to grow mold or rot can also affect storage boxes and the documents within them.

To be fully on the lookout for conditions that can encourage mold to invade, records center managers should be fully aware of why and how mold fungi form and spread.

FUNGUS AMONG US

The Kingdom of Fungi is neither plant nor animal but instead a group specialized spore-producing, single- or multi-cellular organisms found virtually anywhere on the planet.

Fungi are responsible for important ecological processes such as biodeterioration. Together with bacteria in soils, fungi degrade plant and animal debris into simple chemical components that can be reused by nature. In fact without fungi the world would be a much messier place. These extremely prolific organisms are also known to make up approximately 25 percent of the world’s biomass.

Although fungal cells resemble cells of higher plants, fungi differ from plants in that they are unable to perform photosynthesis. Instead, fungi survive by secreting enzymes that degrade organic substrates into soluble nutrients that are readily absorbed. Fungi reproduce by making spores that are invisible to the human eye without magnification (sizes ranging from 2 - 20 microns).

Most spores can remain suspended in air for a long time until they settle on surfaces. When spores settle on sufficiently moist organic materials, they germinate and a colony is formed. As fungi germinate and grow, they form branching filaments called "hyphae," which combine to form the majority of the visible mass.

As fungi continue to grow, the hyphae develop into what is called a mycelial mass. Several mycelial masses have a fuzzy appearance when viewed by the naked eye. As the fungal mass matures, reproductive bodies called conidiophores that resemble stalks develop from the hyphae and produce conidia, also known as spores.

THE ROLE OF MOISTURE

Basically, the equation for mold growth is very simple: Mold spores, plus sufficient moisture, plus sufficient nutrients equal active growth. It should be noted that temperature is an additional factor in the equation but because most indoor environments are kept at temperatures that are very conducive to active mold growth it will not be discussed. However, it is safe to say that if the temperature range is between 40 and 100 degrees Fahrenheit, mold can actively grow and remain viable.

The problems occur when mold spores come in contact with building materials (e.g., sheetrock, wallpaper, carpet, ceiling tile, etc.) that have sufficient moisture content to support active fungal growth. If the moisture content in substrates is in the proper range for a sufficient period of time, a mold problem can develop quite rapidly. Once growth begins, it amplifies quickly, releasing potentially millions of spores into the air and degrading organic building materials and other carbon-based sources.

Mold spores are almost always present in outdoor and indoor air, building materials are manufactured with products that are rich with nutrients, and indoor temperatures must remain at a comfortable level for human occupancy. Therefore, moisture is the best factor to manipulate for eliminating or controlling mold growth.

Several buildings and homes develop mold growth from a single water intrusion from a leaking roof, window or pipe. The water loss could be an acute catastrophic event or just a slow chronic problem that goes undetected for a considerable length of time.

Mold can grow undetected inside of a wall cavity, behind vinyl wallpaper and anywhere the moisture level and nutrient availability are sufficient. It is critical that a building is dried immediately and sufficiently after a water intrusion. Several facilities have mold amplification sites that resulted from improper water mitigation practices.

Either the water in the building was not mitigated in a timely manner (the EPA recommends within 24 to 48 hours) or the building materials were not dried sufficiently, and moisture remained in the substrates. A qualified contractor should be contacted immediately after a water loss is discovered. Selection of qualified contractors is crucial. They should be experienced and have the resources to properly dry and dehumidify the entire building.

Building managers should be proactive and educate the appropriate maintenance personnel in the detection and mitigation of water losses. Several losses, if detected early enough, can be handled in house and may not require the services of an outside contractor.

Another very common reason that mold develops in a home or building is because of poor stewardship. Some buildings are basically neglected and the building staff rarely employs proactive maintenance practices. The heating, ventilation and air conditioning (HVAC) system can be the cause or the cure when it comes to indoor mold growth. Improperly maintained, the HVAC can become the mold amplification site in light of condensation and buildup of debris.

Excessive moisture-generating activities can contribute to the problem and raise indoor relative humidity above 70 percent, which is ideal for mold growth. Even when exterior water sources are minimized, moisture in the indoor air can build up from poorly vented combustion appliances, showers, cooking, laundry, etc.

Damp, unventilated basements are perfect breeding grounds for opportunistic mold spores because there is usually excess moisture, sufficient food supply and continuously stagnant air.

The following are various successful strategies that can aid in the control of inside humidity and moisture: