Condensation
High humidity level in a dirt crawl space, cool surfaces such as the earth at 55 degrees,concrete and metal surfaces will sweat with water vapor condensing out of the air. This causes rot, smells and is a water source for critters.
CleanSpace liner
Clean space liner is carefully cut and installed. The workers will usually be working in their socks to keep the liner clean. That's how clean your crawl space will be.
Outside Air
Most dirt crawl spaces are vented to get the moisture out. The problem is that the vents let warm humid air in during the summer. This adds moisture to the crawl space, and makes the house harder to air condition as all this moisture needs to be wring out of the air
Bugs & Critters
Dirt Crawl spaces are great place to live, thrive and reproduce if you're a bug. There is an even temperature, moisture, damp wood and shelter. Spiders, beetles, centipedes termites, and all kinds of other insects are found in dirt crawl spaces.