Crawl Space Vapor Barrier in Chattanooga, TN

A vapor barrier is the foundation of any crawl space moisture control system in Chattanooga. But the word 'vapor barrier' covers products ranging from a $50 roll of 6-mil plastic from the hardware store to a 20-mil reinforced liner that's part of a complete encapsulation system. The difference in performance is significant.

The problem with basic vapor barriers: 6-mil plastic covers the ground but tears easily, doesn't seal at the walls or penetrations, and doesn't address moisture coming through the walls or foundation vents. In Chattanooga's humid summers, ground vapor is only one of several moisture sources in an unencapsulated crawl space. A basic vapor barrier reduces ground vapor somewhat but doesn't prevent condensation from humid air entering through vents.

A professional encapsulation vapor barrier system uses 20-mil reinforced polyethylene, runs up the walls and is sealed at the top, wraps around all piers and penetrations, and seals all seams with approved tape. Combined with sealed vents and mechanical dehumidification, this creates a conditioned crawl space that maintains appropriate humidity year-round. The performance difference between a basic 6-mil sheet and a complete encapsulation system is dramatic, especially in Chattanooga's summer humidity.