Any crawlspace is susceptible to moisture and deterioration problems because of contact with the earth. How to deal with these moisture problems will vary depending on your climate and your home’s construction. However, in the upstate a moisture barrier
, also called vapor barrier, is usually a plastic membrane, installed to block the flow of air in your crawl space. The main purpose of the moisture barrier is to prevent the passage of water vapor that is contained in the air. The common material used for moisture barriers in a polyethylene plastic that is 4 to 6 mm thick.