Here are some insulation options for a crawl space with a dirt floor:
Encapsulation: One effective method is to encapsulate the crawl space by covering the dirt floor with a heavy-duty polyethylene vapor barrier. The barrier should be sealed around the perimeter and any seams to create an airtight seal. This will prevent moisture from entering the crawl space and improve indoor air quality. Fiberglass or foam insulation can also be installed on the walls and rim joist above the crawl space.
Spray foam insulation: Another option is to spray foam insulation on the walls and rim joist above the crawl space. This will create an airtight seal and prevent air leaks that can cause energy loss and moisture problems.
Regardless of the insulation method chosen, it is important to address any moisture problems in the crawl space before insulation is installed. Moisture can lead to mold growth, wood rot, and other issues that can compromise the structural integrity of the home.