top of page

Mold Information

Molds digest or "eat" the materials they are growing on.  Outdoors there is organic matter such as dead plants or dead animals.  Indoors mold likes to grow on carpet, cardboard, paper, clothes, leather, drywall, wood, insulation, wallpaper glue, and on food.  For the most part molds enjoy the same temperature that we humans do.  The thing that we can control and need to control to prevent mold growth is moisture.  If a mold colony's environmental conditions become unfavorable, instead of dying it can lay dormant until conditions become right again when it can continue to grow.


Conditions for Mold Growth in Houses

Mold problems cannot develop in houses unless there is a moisture problem. The moisture accumulation might be caused through humidity, condensation, or water intrusion from leaks, spills, floods, etc. Most molds only require suitable materials to be wet for 24-48 hours before they can grow.

Moisture is needed in a home for mold to grow.  Typically water gets into the home through floods, ice daming, pipe leaks, roof and chimney leaks, leaks around windows, dishwashers, leaks around the shower and tub are also common, and from other building envlope penitrations.  Water vapor can come up through the concrete foundation and dampen beneath the carpet in the basement, or from showering if the bathroom vetalation is not adaquite. A big source of moisture is warm moist air coming into the basement especilly during the summer, and then condensating on the cool basement surfaces.

Another big problem can be an oversized air conditioning system.  Idealy a properly sized system is a system that is designed to run continuosuly during the hottest days of the summer.  An oversized system will cool the house off fast and then shut down fast.  That short cooling cycle will not take enough moisture out of the air.  We want a smaller system that will run continously on the hottest days so that the moisture will condensate over the air conditioning cooling coils, and get piped/pumped away.  This dry and cool condition is then much more comfotable than the damp and cool (clammy) condition.  A small system running longer, cost the same to operate as a larger system with a short run cycle time.

With an oversized system the moisture may even become visible as condensation on tables and walls, or hide in the HVAC duct insulation.  Sometimes these cold ducts run through the attic where they contact moist air, and then the condensate drips down onto the second floor ceiling.

Once formed, the spores of mold will begin to be released into the air and spread to create new mold colonies. If a spore lands on a suitable material and other environmental conditions are suitable then the spore can germinate into a new mold colony.


What is Toxic Mold?

Out of the several hundred thousand species of molds, there are some different species which are known as toxic molds because they can release mycotoxins which are toxic to humans and animals. Some of the most common toxic molds are:








Not all Black Mold is Toxic Mold

Not all mold that appears black or dark is toxic. This is why if you find black mold which you suspect is giving you toxic symptoms then you should have it tested to identify the species of the mold before taking any drastic measures such as moving out or getting rid of your belongings


Why is Toxic Mold More of a Problem Now?

Toxic mold species have always existed of course but recently they seem to be more of a problem. One reason is because of new building construction codes which came about during the 1970s in response to the energy crisis. These codes aim for higher conservation of energy which requires new buildings to be more airtight.

This means that buildings are less ventilated, not being able to "breathe" as freely and pockets of moist air can be trapped for long periods of time, potentially leading to mold growth. Also many of the building materials used today are very well suited for mold growth.

Toxic Black Mold Problems and Sick Building Syndrome

Mycotoxins produced from toxic mold is one of the major causes of sick building syndrome. If there is a toxic mold infestation in one part of a building the mycotoxins produced from it can quickly spread throughout the building in the air conditioning affecting everyone throughout.

Mold Inspection

If you are concerned about the presence of mold in your home or building, the number one priority  is the health of those living or working in the building. A complete and thorough assessment checking for humidity and moisture, as well as visual inspection that frequently involve the collection and laboratory analysis of air or specimen samples, is sometimes appropriate. Often, it makes more sense to simply take a step back and discuss with an expert your situation and what direction is best for YOU.

In many instances, mold contaminated homes and buildings need to only eliminate the source of the mold and clean up the resulting contaminant. Still, in other situations, where the mold source is not obvious and/or the type of fungi needs to be specifically identified, mold inspection, testing, sampling and identification, may be appropriate.

With Dunn Environmental Inspections you'll get:

  • Over 30 years of experience in the environmental industry

  • Laboratory testing performed by American Industrial Hygiene Association (AIHA) accredited and proficiency tested microbiology laboratories


Mold Health Effects

Molds are suspected to be a major source of indoor allergens and may also trigger asthma. The types and severity of health effects associated with exposure to mold depend, in part, on the type of mold present, and the extent of the occupants' exposure coupled with existing sensitivities or allergies.

Molds produce tiny spores that reproduce. The spores waft through the indoor and outdoor air continually. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on in order to survive. As the mold begins to grow, mold spores will be produced and will spread to other areas. Mold can grow on nearly any surface if the conditions are right. When moisture or water accumulates indoors, mold growth will often occur, particularly if the moisture problem remains undiscovered or un-addressed. There is no practical way to eliminate all molds and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.

bottom of page