Say goodbye to the vented crawlspace. Encapsulating the crawlspace by insulating the walls and installing a heavyweight ground cover is gaining favor as a sensible way to control moisture problems.
Adding a small opening in a supply duct running through an encapsulated crawlspace is an easy, inexpensive way to dry out the crawlspace. Although commonly done, this approach doesn’t work well to address moisture when the HVAC is not running.
Although the builder insulated all the above-grade walls and the attic with closed-cell spray foam, he left the crawlspace vented to the outside. The result: mold growing on the HVAC system.