Q: I’m allergic to mold. What can I do inside to improve my health?
A: To live in a home that will not make you sick, it is important to think about the basics.
Molds need five things to survive and thrive. Get rid of one of the five, and you get rid of most of the molds. These five things are mold spores, mold food, temperature between 40 and 100 degrees Fahrenheit, oxygen and relative humidity of about 70 percent.
Mold spores are everywhere. They particularly thrive in decaying organic matter (leaves, old lumber, rotting decks, deflated basketballs, etc.) and come into the house hitchhiking on air through open doors and windows and all of the tiny cracks that permit air leakage. By building a tight house, you can limit the amount of air leakage and therefore the amount of mold spores coming in.
At the same time, as you go in and out during the day, mold spores will be coming in with you. Installing a good air filtration system — such as an extended surface area (6-inch pleated) filter or a HEPA filter — can also reduce the number of mold spores in the air, although it will not be as effective for the colonies that have moved into the carpet or onto the shower curtain. In other words, while you can reduce the level of mold spores entering and floating around your house, it is more difficult to eliminate them.
The second necessary factor for molds is something for them to eat. Unfortunately, molds are not very picky, and they will consume just about any carbon-based material — wood, sheetrock paper, paint, soap scum, skin flakes, hair, etc. These materials do not even have to be carefully sealed in plastic containers in the refrigerator for molds to thrive. Given the right conditions, they can reproduce right in your living room carpet.
While we can certainly reduce the amount of mold food by cleaning the house and potentially eliminating some of their favorite eating places (like carpet), we cannot completely eliminate mold food from our homes.
The third factor is temperature. However, since molds like temperatures between 40 and 100 degrees, controlling them in this manner is less realistic.
Finally, molds need moisture. They thrive when the relative humidity is about 65 or 70 percent. Control the amount of moisture in the house, and you can control mold growth. To control moisture, start by thinking about where it is coming from. Is rainwater getting in or under the house? Is groundwater seeping up into the basement or crawl space? Is humid air getting into the house from the outside? Are you generating moisture by cooking, bathing, washing clothes, etc. that is not being vented to the outside? Is there a plumbing leak?
Once you identify the sources of moisture in your house, you can develop strategies for controlling it. Once you control the moisture, you control the mold.