What type of material should cover exposed ground areas in crawlspaces?

The correct response is to use a minimum 6-mil layer of polyethylene sheeting to cover exposed ground areas in crawlspaces. This material is specifically designed to serve as a vapor barrier, which helps to prevent moisture from the ground from infiltrating the crawlspace area. Controlling moisture is crucial in crawlspaces because high humidity can lead to problems like mold growth, wood rot, and pest infestations. The 6-mil thickness provides an adequate level of durability and protection against ground moisture compared to thinner materials that may tear or degrade over time.

In addition to its moisture control capabilities, polyethylene sheeting also contributes to energy efficiency by helping to maintain consistent temperatures within the space. This can lead to benefits in overall home energy usage and indoor air quality.

Other materials mentioned, like fabric, concrete, or grass, do not serve the same purpose. Fabric lacks the necessary moisture barrier qualities, concrete is impractical and costly for this application, and grass would not provide effective protection against moisture intrusion. Choosing a proper vapor barrier is crucial for maintaining a healthy crawlspace environment.