Crawlspace Encapsulation - American Basements & Crawlspaces | Crawl Space Repair | Exposed dirt or gravel crawlspaces can be home to excess moisture, humidity, mold or mildew. Waterproofing your crawlspace is an important way to protect your home. Installing a concrete floor in a crawlspace is one way to reduce water issues. Because dirt and gravel crawlspace surfaces allow permeation, concreting or installing a vapor mat barrier.