Crawl space insulation is important to consider. The cool air from crawl spaces can come up and affect the comfort of your home. Any vents or pipes in the crawl space will also be effected if your crawl space isn’t insulated, which will affect their efficiency.
In many houses’ crawl spaces fiberglass is the main form of insulation. This is not the most effective choice of insulation. The way it is often installed, the batts don’t fit together properly and are prone to shifting around. This results in a lower R-value for your insulation. Fiberglass also can get wet while in the crawl space of a house, which again will lower the R-value. For these reasons, fiberglass batts are generally not recommended.
Rigid foam is the best option for crawl space insulation. The installation of rigid foam insulation is usually against the wall of the structure, which helps keep it securely in place and won’t allow for gaps for air to escape. The rigid foam board isn’t affected by moisture like fiberglass is, and will keep the R-value, improving the effectiveness of your home’s insulation.