Humid climates cause high humidity in the crawlspace. High humidity and moisture in the crawlspace promotes the growth of mildew and mold that can cause structural damage and unhealthy air below the sub floor that seeps into the home environment. Encapsulating or conditioning a crawlspace creates an environment that can be controlled. The company House Smarts prepared a great video explaining how to encapsulate the crawlspace. Crawl Space Door Systems, Inc. has durable plastic crawlspace doors and vent covers to seal the foundation when encapsulating the crawlspace.