When building a house, the foundation for an energy efficient home is, well, the foundation. In this video, you'll see a pier and beam house with a conditioned crawl space, similar to that of a short basement; the closed cell spray foam will increase the efficiency of this house. First, what is a pier and beam house? This refers to the type of foundation; concrete piers run into the ground (almost 40 feet down, into the bedrock), and the corresponding beams support a "floating slab" floor. The resulting crawl space requires some work to become a "conditioned" crawl space.In this video, Matt Risinger consults with a colleague to explain everything you need to know about closed cell spray foam.After sealing the seams to prevent any termite infestation, the crawl space is ready for the closed cell spray foam. The closed cell foam creates an air and vapor barrier, which keeps moisture to a minimum.Closed cell foam doesn't absorb water—after spraying two inches of closed cell foam, there is 0% permeability. This closed cell foam is rigid (the opposite of your kitchen sponge). Remember the magic number, two; just two inches of closed cell spray foam will prevent moisture from seeping through the concrete stem wall. Besides the below-grade crawl space, where else can you use closed cell foam? Watch the full video to find out.