We at Moldstoppers have learned a lot over the last 10 years about crawlspaces and basements. The science regarding the treatment of moisture and mold in these areas has changed drastically, and we have kept pace.
The key is relative humidity. You must keep it below 50% in order to keep mold from growing.
Do not let moisture to get in by encapsulating a crawlspace.
Keep moisture down by dehumidifying the basement or crawl space.