What is the minimum weight of the polyethylene film recommended for covering the ground in an unheated crawl space?

The recommended minimum weight of polyethylene film for covering the ground in an unheated crawl space is 6 mils in thickness, which typically corresponds to a weight of around 55 lb or more per 1,000 square feet. This minimum weight is essential as it provides adequate vapor barrier properties, preventing moisture from the ground from entering the crawl space. Using a heavier film reduces the likelihood of tearing during installation and provides better durability over time. The role of this barrier is crucial in controlling moisture levels, which can help prevent mold growth and structural damage. Therefore, the choice of 55 lb aligns with industry standards for crawl space encapsulation, ensuring the area remains dry and protected.