Nearly 19 million homes in the United States have crawl spaces. The trouble with crawl space construction is it can potentially affect the living space above it and have more wood rot problems than other types of construction.
It has been proven that warm, humid outdoor air brought into the crawl space through foundation vents in the summer can lead to increased moisture levels in the crawlspace and eventually into the home. The air introduced through the vents into the crawlspace does not always move side to side but instead will move upwards, which is called the “Stack Effect.” This Stack Effect draws air inward from every crawlspace vent and up into the living space, resulting in increased humidity levels and musty smells throughout the entire home.
Wood rot only occurs when the moisture content is above the fiber saturation point, about 27% to 28% wood moisture content. In order to keep this in perspective, consider the following:
- Fresh-cut wood is typically around 200% moisture
- Kiln-dried wood has seven to 10% wood moisture content
- Air-dried wood has a typical moisture content of 19%, but that varies with the relative humidity (RH).
The 28% wood moisture content necessary for rot to occur doesn’t come about from just high humidity. Water has to make contact with the wood before the wood rots. Any time the relative humidity is over 70%, you can get spot condensate because temperatures vary throughout a crawlspace.
A solution to this problem is the new Santa Fe Force Dehumidifier that features dual exhaust and is specifically designed to provide the optimal amount of airflow in crawlspaces and basements. This airflow helps prevents spot condensate, and in combination with the dehumidification, protects the crawlspace and living space.