Seasoning of wood is a process whereby freshly cut wood is dried so that most of its moisture is removed. Seasoning can be done through the use of a kiln or through air-drying the wood.
Air-drying wood can take months to complete, depending on the wood type. For most hardwoods, the air-drying process takes about six to nine months to reach a moisture content of 20 to 25 percent. To air-dry wood, workers stack it outdoors with enough space between the wood pieces to allow airflow around them. As the air flows around the stacks of wood, it pulls the moisture slowly out, resulting in seasoned wood that can be used for a variety of building projects.
The ends of air-drying wood tend to dry out more quickly than the sides of the wooden pieces. To avoid having the ends dry too quickly, they are usually sealed or painted to close off the pores, slowing the effects of the air flow around them.
Air-drying wood does have some issues, though. The wood requires space to be laid out, as opposed to quickly being seasoned in a kiln. This land becomes a costly addition to the drying process. The stacked wood also poses a fire hazard that can result in the loss of large sections of the stacked materials.