Mold

E:zero An anti-mold vaccine for your home

The most recent statistics from the U.S. Census Bureau show that there are more than 126 million homes and apartments in this country. Most homes will be subjected to some type of water damage during their lifetime, caused by everything from leaking roofs and broken water pipes to floods. At the same time, homes are exposed to less obvious water intrusion caused by high relative humidity and condensation, which is often a bigger concern because it frequently remains undetected until there is a problem.

In recent years, there has been high-profile mold litigation that has helped people understand the severity of mold related diseases. These cover a wide spectrum of illnesses, from those causing minor nuisances to those posing serious impacts, such as chronic sinus infections and hay fever-like symptoms. Mold may also trigger asthma attacks and allergic reactions, and increase peoples susceptibility to colds and flu. Those most at risk are small children and the elderly.

What is mold?

Molds are microscopic fungi which grow on plants and fibers such as wood or paper. Typically, molds thrive in damp, musty locations such as attics, outside walls of homes, basements, and crawlspaces. Mold reproduces by releasing tiny spores which float through the air. Once the spores settle in wet or damp areas, they will start to grow. Mold spores are really everywhere inside and outside; however, it is important to keep them to a minimum to avoid health problems. There are many types of mold, from fairly benign to very toxic varieties. As an example, black mold is commonly used to describe a slimy, greenish-black substance which can result in serious health risks. This infamous mold is also known as Strachybotrys chartarum, or more often as Strachybotrys atra. In some cases, it has been closely linked to the death of babies by respiratory bleeding, and as a contributing factor to illnesses such as asthma and bronchitis.

Typical Scenario of a Home Infested with Mold

This is the short version of a sad story which we encountered in 2004. The story began with a beautiful home in Santa Monica, California which was only about 3 years old. It was insulated with fiberglass. Unfortunately, the ventilation was insufficient, and the family did not make the connection when the wife suffered almost constant headaches and the children developed chronic bronchitis. In fact, their suffering increased for an entire year until they finally asked an expert to analyze the home. The diagnosis was fast and bad: basically all basement walls were infested with mold, as were a number of areas on the first floor and in the attic. As a result, all drywall installed in the basement, along with the fiberglass insulation, had to be removed, and the walls dried, disinfected, and finally insulated with spray foam. The infected areas on the first floor underwent the same procedure. The cost of remediation exceeded more than $100,000, not even counting the suffering by the family, the worry that their health damage might be permanent, and the disruption of everybodys lives. Of course, this does not happen to everybody; however, it is a far more common scenario than widely assumed. Had the house been properly insulated with the E:zero spray foam insulation system, and the family been educated on managing interior humidity, untold suffering and great expense could have been prevented.

Keeping mold at bay

Mold needs food, air and water. There is a lot of food for it in walls, from the paper backing of the drywall to the wood studs. If the wall is insulated with fiberglass, then the whole wall cavity is also airy. There is also an excellent chance that the building envelope is not air-tight enough to prevent the penetration of moisture-laden air into the wall cavity. Now all the elements are in place for your very own, toxic mold farm: food, air, and -- like magic -- water caused by condensation. Even if the house is fairly air tight, micro cracks and gaps will develop over time since the building moves with the temperature changes and wind. The only way to keep the mold risk down is by massively drying the interior air with the help of air conditioning, dehumidifiers or extreme ventilation. The relative humidity level must be kept at 60% or less in order to prevent mold. Its a different game if the wall is insulated with E:zero spray foam solutions. E:zero provides the all-important air barrier, which prevents the uncontrolled infusion of moisture into the building envelope. It is still important to manage the interior relative humidity; however, this will now be dramatically easier since the building is air-tight. Likewise, the foam is much more likely to permanently prevent cracks because it stiffens the building envelope and is flexible enough to not crack when normal building movements occur. A final point: unlike fiberglass, foam is not a food source for mold, and thus the available surface areas for mold to grow on are drastically reduced.

Condensation The Failing Building Envelope

Condensation occurs when the relative humidity exceeds the capacity of the air to hold any more moisture. In this case, it starts raining or the water starts to condensate. On a warm summer day, a glass of ice water will be wet on the outside. This is condensation, the same thing that happens in the wall. In the left half of the drawing below, cold air from the air conditioned space enters the wall cavity, while there is warm humid air penetrating from the outside. Condensation occurs where the air drifts collide, providing water for mold spores. Food and air are already abundant, so mold growth starts.

In the right half of the drawing, the wall is sprayed with E:zero foam insulation. Cracks in the building envelope are sealed, and no air penetration takes place. Even vapor drive, theoretically an issue, will be small enough that there is no condensation. It is not important if the wall cavity is filled entirely with foam. The only important factor is the thorough and complete coverage of the wall.

Summary

Keeping a home free of mold requires control of the interior relative humidity which includes mechanical ventilation. Only E:zero insulation foam makes this easy by eliminating condensation under all typical conditions. The key element is the uncontrolled air and moisture infiltration, which is reduced by about 85% compared to fiberglass.