For decades homes in the Southeast have been commonly built on crawlspace foundations. All the while the codes and general wisdom have said to ventilate these spaces to reduce moisture and its related problems such as mold. However more recent research and studies have shown that this actually makes matters worse for homes here in the humid Southeast of the country.
What we now know is that in the hot humid months these crawlspace vents are simply sucking moisture into the area and creating a wonderful environment for mold to grow wild. Common problems related to moisture in the crawlspace or home include mold damage, musty odors, condensation on air conditioning ductwork, buckled hardwood floors, insect infestations and rot in the home’s wooden framing members.
The latest evidence shows that a home with a fully sealed crawlspace perform better all year round, staying dry, saving energy and resisting mold. By ‘sealed’ what is meant is no vents and that both the ground and the walls are covered in thick poly that is properly joined to create a lasting effective moisture barrier.
The website www.crawlspaces.org, offers extensive and detailed information on how to properly design a sealed crawlspace and the science behind the new thinking. Though local building codes are changing, most new homes with crawlspaces continue to be built with vents. So if you're building a home or planning to this is a very important issue to be aware of as it can save you money on cooling and maintenance as well as protect your family's health.
If you already own a home on a crawlspace in a hot humid region, then the question has to be to seal or not to seal it. It's not an easy straight forward question to answer since any change you make to an older home will have impacts elsewhere in the system. I just bought an older house with a crawlspace so look forward to further discussion on the subject as I assess whether to seal it and how.
