THE THREE PRIMARY SOURCES OF MOISTURE
Moisture Source #1: Air Leaks
Air. It can leak into a home through walls, roofs and floors. This kind of uncontrolled airflow leads to moisture that can cause mold and rot, as well as indoor air quality issues and increased home energy costs.
Moisture Source #2: Diffusion Through Materials
Essentially, this is when moisture spreads through permeable materials. For example, if soil becomes saturated with moisture, that moisture can then permeate adjacent crawl space walls. Once inside the walls, the moisture will soon enter the crawl space itself. Installing a vapor barrier can help reduce this common problem.
Moisture Source #3: Internal Moisture
On average, a family of four produces 2 pints of water an hour, or up to 25 pints of water a day, simply by washing dishes, taking showers, cooking and even breathing.