Example of how the crawl space of a home should be ventilated

Should Crawl Spaces Be Ventilated?

Many residences have crawl spaces to give homeowners access to their utility systems. Unfortunately, crawl spaces tend to trap moisture, which can lead to the growth of mold, mildew, and rot.

Issues With Enclosed Crawl Spaces


Enclosed crawl spaces are typically built with solid concrete or masonry foundation walls. These extend to the structure’s footings, where crawl spaces come into contact with porous materials, like wood or insulation, that trap water when they get wet. The resulting humidity often promotes the growth of fungi and mildew, which can cause people to get sick.

The Assumed Benefits of Ventilating a Crawl Space


Crawl space ventilation allows air to circulate under the floor, potentially preventing the buildup of moisture. However, ventilating a crawl space can increase a home’s energy bills while not keeping it as dry as many believe.

To Vent or Not to Vent


Research conducted by Advanced Energy, a global energy company, yielded surprising results about the effects of ventilating a crawl space. They monitored a modular housing development in Baton Rouge, LA, which is hot and humid for most of the year. They also monitored 12 stick-framed homes in the colder, drier climate of Flagstaff, AZ. Their research found that unvented crawl spaces stayed drier than vented ones, no matter how hot or humid it was.

Crawl Space Encapsulation


Because a significant amount of air exchange takes place in crawl spaces, having mold or mildew in this part of the home can seriously affect indoor air quality. Encapsulating a crawl space in a polyethylene vapor barrier can drastically reduce moisture infiltration without relying on expensive ventilation options. Encapsulation can also lower energy bills and help heating and cooling equipment last longer between HVAC maintenance checkups.

Encapsulating a crawl space is an effective way to prevent moisture from being trapped in crawl spaces. For decades, Advanced Air Solutions has helped people in Wilmington, NC and the surrounding areas maintain a high level of air quality in their homes. For more information about keeping crawl spaces dry, call 910-791-7888 or contact us online.

Photo Courtesy of Jesus Rodriguez.

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