Why You Need Crawl Space Insulation

There are several reasons why crawl space insulation is a smart investment for a homeowner or building owner. Basically, crawl space insulation mitigates damage caused by moisture and the extra cost caused by air inefficiently leaking and mixing between the crawl space and livable space. Though moisture and energy efficiency may small, either one of these variables can generate larger problems and costs down the line if not managed properly.

Open vs Closed Crawl Space

Both styles can serve as a foundation for the house as well as a storage space. Closed crawl spaces are designed to be within the thermal envelope of a house, thereby automatically reducing some of the moisture and efficiency problems that can impact open crawl spaces.

Moisture Control

A crawlspace may not be sealed perfectly, so a vapor barrier covering fiberglass insulation should be installed. Remember that concrete can develop cracks over time. Combined with soil moisture permeation, condensation and/or leaks, even a closed crawl space can produce mold and generally cause problems. Open crawl spaces have an extra variable to consider: cooling from the home’s HVAC system. Hot outdoor air can hold a lot of water vapor, so its relative humidity is low. When that hot air releases into a cooled crawl space, it cools but the moisture content per unit volume of air doesn’t decrease. Relative humidity goes up and condensation soon follows. With condensation and generally high moisture, bugs and mold degrade wood subflooring. Additionally, rust can form on exposed metal parts, making future repairs or alterations much more complicated and costly than they would be with preventative measures such as crawl space insulation.

Energy Efficiency

Another reason for installing crawl space insulation is efficiency. A sealed crawl space is extra air in the house that is heated and cooled as much as the living space. Just like open windows decrease efficiency of heating or cooling and lead to larger bills, a crawl space without insulation is pretty much the same thing.

Crawl spaces can be ideal foundations for a home. They reduce the risk of concrete cracking and uneven settling that plagues slab foundation structures. On the flip side, they are cheaper and simpler to build than full basements while still providing ample storage space even if livable space square footage is modest. Though builders recognize homeowners’ concerns about moisture and high heating/cooling bills, crawl space insulation may not be ideal, especially over long time periods. Property owners who supplement crawl spaces with insulation such as fiberglass and polyurethane vapor barriers will have extra protection against the New England weather, soil moisture, and eventual wear-and-tear that affects crawl space construction.