Buckling Hardwood Floors Above Vented Crawl Spaces | | Ask the Expert

In this episode, Rob Videon helps a customer in Macon, GA, who is very upset with the fact that his home’s hardwood floor, installed only two years ago, is beginning to buckle and he wonders if it has anything to do with the dirt floored, vented crawl space underneath.

Rob explains that a vented crawl space is basically a housing nightmare waiting to happen. There is water constantly evaporating from the ground, and then there is humidity from the outside air being brought into the crawl space through the vents during the summer

The crawl space vents formerly required by most building codes were supposed to help dry out the crawl space, but these building code requirements were based on a scientific fallacy. Thanks to current developments in building science we now know that air doesn’t flow through the crawl space vents. Once it enters the crawl space, the air moves upwards due to a phenomenon known as the “stack effect”.  All that moisture in the crawl space is absorbed by the wooden structures. Wood with high moisture content begins to warp, buckle and eventually become breeding ground for mold and dry rot.

To stop moisture from causing all sorts of problem, the best option is to seal the entire crawl space with a vapor barrier, and use a crawl space dehumidifier to keep relative humidity at optimum, and safe levels.