A key to reducing the chances of attracting wood destroying organisms includes having a vapor barrier down on the soil in the crawl space. Without such a barrier, the moisture in the soil evaporates up into the crawl space and even up into the interior of the home. That leads to the wood being moist and damp all the time. In my readings and many homes, this one in Burlington area, I find that the relative humidity reading are much higher in homes that do not have vapor barriers. High relative humidity is a conducive condition and a contributor to mold growth. Wood destroying organisms that are attracted to moist crawl spaces, in my region of the country, include two species of termites, carpenter ants, moisture ants, anobiid beetles and wood decay fungi or rot. The crawl space below needs to have a vapor barrier. Also, if the plastic needs to be held on place, to keep it from shifting, never use wood. Instead use rocks, concrete or bricks - material that is not appealing to wood destroying organisms.
Thank you for stopping by.
Steven L. Smith