Mold Info

"I found mold in my home. Should it be remediated or sanitized?" We get this question often. Part of the confusion comes from the fact that there is conflicting information among the states that have mold laws in place. More importantly, none of the thresholds established by these states considers the type of mold, the moisture source feeding the mold, or the reality that even a very small amount of mold (even smaller than the established square footage threshold) could be harmful to the occupants.

To clarify a bit better, let's define the words that are often used when mold appears: remediation and sanitization. Remediation is the actual removal of contaminated building material to locate and repair the moisture/water source that is feeding the mold. Sanitization is the process of using a fungicide to lower the microbial count by cleaning the surface and does not involve demolition. These are clearly two different approaches to addressing mold, so how do you decide when to use which process?

When determining how to best address a mold problem, it’s important to consider the amount of mold, the type of mold, and the moisture content of the substrate behind it. Remediation would take place when:

There is 10 square feet of visible mold. When the states established their thresholds (10 square feet was the most conservative), they did not consider whether that mold would be in one place or spread throughout the environment. We suggest that the 10 square feet of visible mold would represent mold either contiguous or cumulative in a single air conditioning coverage area. This allows us to segment the project based on whether the mold has been or could be spread throughout the entire living environment. For example, in a two- story home where there is an air conditioning system that covers the first floor and one that covers the second, with the second floor contaminated and the first floor not, a remediation process could be isolated to the second floor. Since air still travels to all parts of the home, a whole house sanitization should follow any remediation, regardless of which part of the home the remediation took place.
Zero-tolerance mold is present. Certain types of mold are considered to be zero-tolerance either because they are water sensitive or highly toxic, and these should always be remediated: Stachybotrys, Chaetomium, Fusarium, Trichoderma, and Memnoniella.
The moisture content of the substrate on which the mold is growing is greater than 17%. Mold needs water to grow and can get that water from the air (like air infiltration problems, elevated relative humidity, or poor insulation) or from a water source (leaky pipe, roof leak). When moisture content is elevated behind mold growth, remediation is usually recommended so that the water source can be removed or repaired, and the remaining areas can be treated and dried out.

These three factors provide a benchmark for determining if remediation or sanitation should be used in addressing mold. Although mold is a serious issue that must be resolved, the reality is that, in many cases, remediation is unnecessary and sanitization could suffice. Remediation is expensive, so we’re talking about a less expensive and less disruptive solution in sanitization. If it is appropriate to use sanitization instead of remediation, the process is faster and more cost effective.

Stachybotrys

ZERO-TOLERANCE MOLD

This type of mold grows easily on wood, paper, or cardboard. You may have heard it referred to as "black mold,” albeit these have been used to describe other types of mold too. Stachybotrys mold needs super damp conditions, and it needs days or even weeks to grow fully into its hazardous self. This toxic mold or mycotoxin is not only found in homes but in office buildings too.

Chaetomium

Stachybotrys

ZERO-TOLERANCE MOLD

Chaetomium is commonly found in soil, plant debris, and the air. It takes on the appearance of an almost fluffy, white substance, but as it ages, it turns grey-green (like the picture). This mold can also grow on organic materials such as drywall, fabric, and paper, so be on the lookout for it almost anywhere in your house where there is moisture, houseplants included. Water-damaged materials are a go-to source of colonization for Chaetomium.

Fusarium

Stachybotrys

Trichoderma

ZERO-TOLERANCE MOLD

This type of mold also starts in the soil; it tends to affect humidifiers and plants in the home. Its toxins are believed to harm the circulatory and nervous systems. If Fusarium affects a person, it is typically via ingestion, for instance, by eating some contaminated grain, but it is also possible to inhale its’ spores.

Trichoderma

ZERO-TOLERANCE MOLD

Trichoderma is the most common type of naturally occurring mold in the ecosystem and it serves many useful purposes there. Although you don’t want Trichoderma growing in your home because of the health risks, this mold is widely used to make industrial and agricultural products.

Memnoniella

Trichoderma

Cladosporium

ZERO-TOLERANCE MOLD

This mold is bluish-green in color and sometimes looks like a cobweb or felt when it grows. It can grow on cellulose materials such as wood, carpeting, insulation products, drywall, wallpaper backing, and pretty much anything that is organic in nature.

Cladosporium

Trichoderma

Cladosporium

This type of mold is often blamed for skin lesions, nail fungus, asthma, and lung infections. Cladosporium is a "black mold" that, in highly sensitive people, can cause various allergic reactions. It is known to cause sinusitis and pulmonary infection, which can then become a respiratory infection like pneumonia.

Mucor

Aspergillus

This type of mold is found in soil, and it can work its way into the home. When it has entered the home, Mucor is often found in ductwork and air conditioning systems. It has a whitish to grey coloring, sometimes gets thick, and it can also grow fast.

Aspergillus

This is a more common mold that is found in our regular air supply. Those with weaker immune systems are more susceptible to the effects of aspergillus just by breathing it in. It can lead to lung infections and cause serious allergic reactions to the respiratory system. Aspergillosis is a particular infection caused specifically by this mold type.

Penicillium

Aspergillus

Penicillium

Believe it or not, this mold is often used as an antibiotic against various infections. It’s actually used in food processing. It will grow on walls as well as on different types of food. While Penicillium is a useful mold, it can also be a threat to health and cause medical issues.

Acremonium

Penicillium

This type of mold is of particular concern because it creates nasty toxins that can damage organs, bone marrow, and immune systems. Acremonium has even been linked to problems with a person’s mental ability.