Healthy Basement Living - Mold Facts & Prevention

Mold Facts

What is Mold?
Mold is one of the oldest natural occurring living organisms on earth. Mold is a type of fungus. There are over 100,000 known living species and 200,000 unidentified fungi.

Where Does Mold Come From?
Mold is everywhere – indoors and out – even in the cleanest homes. Mold can enter a home on clothing, shoes, pets, open doorways, windows, vents and through the heating and cooling system. They can exist in dust and can be carried through air and water. Mold can grow within 24-48 hours of landing on a damp, moist base that has food and oxygen available. It is nearly impossible to create an environment that is 100 % mold free.

How Does Mold Grow?
When environmental conditions are right, mold will release invisible spores which develop into unwanted growth.

To grow, mold needs:

• Oxygen
• Organic food source
• Warm temperatures
• Water (or moisture)

"Food" is any organic (living or once living) matter. Mold decomposes the organic matter and uses it as a food source. The decomposition process can also cause damage or destruction to the host material.

Mold can grow in temperatures between 40 and 140 degrees when combined with high humidity. Temperatures between 68 – 80 degrees are the common range for mold growth, when other conditions are also present.

Water sources can be pooled water (often caused by leaks) or damp surfaces (often caused by humidity). Humidity levels over 60% is the known threshold that enables mold growth when other conditions are present.

What Does Mold Look Like?
Mold can be nearly invisible or resemble spots of various colors. It may or may not smell musty. Mold may cover small patches or cover large areas. If you can see or smell mold, a health risk may be present and should be immediately addressed.

Stachybotrys Chartarum (Black mold)

Stachybotrys, commonly called "stachy," is a greenish-black, slimy mold found only on cellulose products (such as wood or paper) that have been wet for several days or more. The mold does not grow on concrete, linoleum or tile.

Mold and Your Health

Molds may cause health problems for those sensitive to allergens. They may cause nasal stuffiness, throat irritation, coughing or wheezing and eye or skin irritation. They may also trigger asthma attacks.

Severely sensitive individuals or those with immune compromised health conditions, such as chronic lung illnesses, may be susceptible to lung infections when exposed to molds. Other serious health effects, particularly infant exposure to the Stachybotrys Chartum mold (black mold), have not yet been positively linked, but are being actively studied.

Stachybotrys and some other fungi may produce several toxic chemicals called mycotoxins. Mycotoxins can be present in spores and small mold fragments released into the air. Once the mold fragments, mycotoxins and spores are in the air, individuals may breathe them into their lungs.

Mold Prevention

The key to controlling mold is to prevent or correct the conditions that allow growth.

Humidity

• Keep relative humidity levels between 40% and 59%.
• Use an air conditioner or a dehumidifier during humid months and in damp spaces.
• Avoid the use of humidifiers.

Temperature
Limit excessively warm temperatures in the home that are known to encourage mold growth. Temperatures over 68-80 degrees Fahrenheit and above can cause mold to develop when combined with high humidity. Temperatures below 50 degrees Fahrenheit will render most molds inactive, or dormant, but will not kill them.

Ventilation
Be sure your home is properly ventilated to control the build up of humidity and moisture in the air. Use exhaust fans which vent outside your home in the kitchen, bathroom. Vent your clothes dryer outside your home.

Air Circulation
Create a living environment throughout the house that includes adequate air circulation to help prevent mold growth. Air circulation helps control moisture levels through evaporation. Open windows, when possible, but only when the humidity outdoors is lower than that inside. Set up fans to increase air circulation. Set up dehumidifiers to lower the relative humidity.

Moisture & Leaks

• Fix moisture or water leaks in walls, roof, windows, basement walls and plumbing pipes.
• Thoroughly clean and dry any areas that have been exposed to flooding within 24-48 hours.
• Remove or replace carpets and upholstery that have been soaked and cannot be dried properly or promptly.
• Prevent pooling water or high humidity levels that results in condensation or dank conditions which allow mold and fungus spores to grow.

More Prevention Tips

• Regularly inspect for mold or mildew.
• Add mold inhibitors to paints before painting.
• Clean bathrooms with mold-killing products.
• Use good construction drainage practices, such as detailing, flashing, and sealing around doors, windows and penetrations.
• Place or adjust outside gutters and drains so that water does not collect near the outside walls. Check gutters and drains regularly to avoid clogs. Place lawn sprinkler systems so that they do not soak outside walls.
• Install the best filters you can afford for your heating and cooling vents. HEPA filters are particularly effective. When replaced regularly, they can decrease the amount of mold spores as well as dust and other materials that allow for mold growth.
• Inspect ceiling tiles (if any) for visual stains which may indicate leaky ductwork and conditions for mold.

Sources:

Centers for Disease Control and Prevention (CDC), "Environmental Hazards & Health Effects: Mold."
Solinet, Preservation Services Leaflet, Sandra Nyberg, Solinet, September, 2005
EPS Molders Association, "EPS Insulation Mold Resistance," November, 2004