How can building materials contain excess moisture?

Moisture in a building can accumulate and dissipate in relationship to: outdoor moisture; indoor moisture; exfiltration of moisture, and diffusion of moisture. The design, construction, and operation of the building are critical to controlling moisture accumulation. Concrete, lumber and surfaces such as wall board or paneling, ceiling and floor coverings can all contain moisture depending upon manufacturing, transporting, storing, and using. Unless lumber is kiln dried and protected from weather, the more common construction lumber used is green and therefore wet. Treated wood containing 19% or more moisture is not considered acceptable. Temperature/ ventilation during construction and once the building is closed and occupied contributes to the moisture load within a building. Concrete may take weeks to months to cure and for the vapor transfer rate to become within the normal range. Adding moisture during construction in the form of water based light weight flooring, tape, texture, ...  more