The effect of moisture damage can be difficult to imagine. To truly understand how your home could be affected, it helps to know that each day, the ground under and around your home releases as much as 19 gallons of water vapor into your crawl spaces and foundation. This can cause rotted joists, sills, and other structural members, blistering exterior paint, and mold. Weatherization helps eliminate moisture at the source through sealing, and eliminates it with proper ventilation.​