The before picture shows another typical crawlspace that has a 6 mil vapor barrier on the ground, which is easily punctured and torn. Also, the crawlspace is vented, which allows warm, humid air to condensate on ductwork that is in the crawlspace during the summer months. During the winter months, the vents and all of the gaps and cracks around the rimjoints/band allow cold, winter air to enter the crawlspace and cause frozen water lines, busted water lines, and extremely cold floors. In these types of conditions, wood can potentially mold, mildew, and rot.
The solution, which you will see in the AFTER picture, is to apply a 20 mil cleanspace liner over the earth and rolled upon to every pillar and all perimeter block walls, sealed at every seam with cleanspace tape. Our 20 mil liner is a very tough seven-ply barrier. It consists of three layers of high strength polyethylene film laminated together with two layers of molten polyethylene, with two layers of polyester cord reinforcement sandwiched in-between. It is blue on one side and bright white on the other. It provides exceptional impact and puncture resistance and brute tear resistance. Both the white and blue sides are protected with UV stabilizers. CleanSpace is treated with UltraFresh antimicrobial finish to prevent mold growth.
We then apply 2 inches of class II vapor barrier closed cell foam around the band board/rim joists, down the block, sealing up all crawlspace vents and down onto the cleanspace liner. This creates a crawlspace that is completely sealed off from all outside elements.