No one wants mold in their home. Mold can cause health problems and damage to the structure of the home and the items in it. Mold prevention, and removal when mold and mildew infiltrate a home, is important to protecting your investment in your home, and moisture control is one of the most important steps in controlling the growth and spread of mold spores.

Crawl space repair is an important part of mold prevention, as it’s an area of your home’s foundation where a lot of moisture can get trapped. However, there are different schools of thought on how to best keep the crawl space dry. One side of the argument says that crawl spaces should be ventilated in order to keep the air in the crawl space from growing musty and stagnant, and the other side believes that an unvented crawl space does more to prevent moisture collection and mold growth.

The Mold Prevention Debate

For a long time, foundation vents were built into home crawl spaces as part of any quality construction project. The thinking of the builders, carpenters, and contractors that worked on houses was that ventilating a crawl space would allow the air inside the home to circulate and keep it dry for mold prevention. Instead of keeping the crawl space dry, ventilation allowed outside air to come in through the vents. The water that would condense and collect inside of crawl spaces caused corrosion, mold, mildew, and rot inside of homes, making crawl space repair necessary.

Once building scientists existed and thought about the problem, the thinking became that crawl spaces should be sealed and insulated. The intent was not only mold prevention and moisture control, but a decrease in energy usage as well. However, some builders and building departments are slow to change: many foundation vents are still installed into crawl spaces, and some codes require vents to be installed.

So is there any truth to the thinking that ventilation is good for mold prevention? Luckily for homeowners, Advanced Energy conducted a study on ventilation in crawl spaces.

The Mold Prevention Study

Advanced Energy is a North Carolina organization made up of building scientists and researchers. Their goal is to build homes that last longer and use less energy, so crawl spaces are something they think about a lot. One report that they released compiled the results of studies of homes in different climates.

The December 2009 study had researchers monitor two sets of homes in different climates. One set of 15 modular housing development homes was in Baton Rouge, Louisiana: a hot and humid environment. The second set was in cold and dry Flagstaff, Arizona, where 12 stick-framed houses were studied. A variety of heating systems, ductwork configurations, and thermal barrier locations were used. A few years before the 2009 study, Advanced Energy looked at homes in central North Carolina to see if mold prevention and energy savings could be achieved. That study concluded that closed crawl spaces accomplished both goals: the question was whether the results would look similar in other climates.

The Effects of Ventilation on Mold Prevention

Ultimately, the conclusion of the report was that closed, unvented crawl spaces are drier than vented ones and therefore better at mold prevention in all climates. The full results of this study, along with other publications and reports about crawl spaces, can be found on the Advanced Energy website.

Crawl spaces that are closed are drier no matter what climate the home is located in, how much insulation is used, or where ducts are placed. Humidity was lower in all of the homes, even in humid homes, where the difference in daily relative humidity was around 20% lower in properly closed crawl spaces. When supplemented with a sealed liner system, the humidity control in closed crawl spaces ended up being more effective—and when humidity is controlled, mold prevention efforts are more effective. A sealed crawl space with no circulating air will not only keep humidity down, but also help prevent microscopic mold spores from entering your home in the first place, making a treated and sealed crawl space an ideal means of mold prevention, no matter where you live.

Mold Prevention and Crawl Space Repair from Acculevel

Water intrusion, mold and mildew growth, settling foundation, and sagging floors are all common crawl space problems, and they’re more related than you might think. Repairing crawl space issues is an important part of protecting the value of your home and the health of everyone that lives there. A crawl space repair expert will have solutions for moisture removal, structural support, and mold removal and prevention. For a free home inspection and basement reconditioning or waterproofing estimate, contact Acculevel online.