No matter where you live, mold can be a very serious problem. Here in Chicago, we have the “perfect storm” if you will, for mold and mildew to grow inside buildings and residences.

I’m often asked how spray foam can fit the strategies to avoid mold. Mold and mildew are subjects my business takes very seriously and in today’s article, I want to help you understand what mold is and how spray foam can prevent it from ever showing up at your home or business.

What is Mold?

You know it when you see it, but at its essence, mold is a naturally occurring fungus that exists in order to break down all types of organic matter.

When the conditions are right, mold can grow almost anywhere. To flourish, mold only needs 3 things:

1. Mold spores
2. A source of food (organic matter of any kind will do)
3. Moist conditions. Most times this means more than 80 percent relative humidity and while it likes warmer temps, it’s been known to live in temps as low as 70 degrees.

Mold spores are plentiful in our home environment, which makes controlling them very difficult.

Building materials are organic in nature (wood, paper, etc.) which act as a food source for mold.

Since we cannot (or we don’t have plans anyway) get rid of the organic materials that homes are made from, it makes more sense to control mold by eliminating moisture and/or controlling temperatures.

This is where spray foam insulation comes into play.

How Moisture Enters Buildings

Moisture enters our buildings and homes in several different ways.

The primary source is bulk moisture via rain or snow. Rainwater will enter the building via construction flaws or improperly sealed rooms. Water that enters in this manner is more substantial than most people realize.

Spray foam should not be used to stop leaks that can occur due to construction flaws, such as leaking roofs or worn-out flashings.

Many types of construction materials, such as wood or concrete, tend to be very porous, which allows moisture to move inside the building or to accumulate in concealed areas.

The most effective way to control this type of moisture is to provide a barrier, also known as waterproofing, or drainage planes to move moisture away from these water-sensitive materials.

While identifying these problem areas is simple, correcting them is very expensive. For example, imagine the costs of excavating a foundation to provide waterproofing or drainage?

Care must be taken to ensure that there are no pre-existing bulk water leaks that can deposit large quantities of water in your home.

Air Leakage and Diffusion

One of the most important reasons for choosing spray foam will be to control air leakage. Air leaks will often be cooled to the point that condensation will occur, which results in the moist conditions that mold prefers.

Spray foam will control air leakage and it insulates exposed surfaces from moisture, causing surface temperatures to be well above the dew point. This basically means that surfaces stay dry, which inhibits mold.

In climate zones 5 and above, a vapor retarder may also be required. This can be provided by the spray foam itself, or a separate vapor diffusion barrier will need to be installed.