Logs that are cut from the butt forest, brought to a mill or to a log-house construction yard, have their bark removed and are used to build a log-house shell (handcrafted log houses), or sent through profiling machines (manufactured logs) are usually referred to as “green” logs if they have not been air- or kiln-dried. “Green” does not refer to color, but to moisture content (MC). The actual moisture content of “green” logs varies considerably with tree species (cedar, fir, spruce, pine etc.), the season in which it was cut, and whether sapwood or heartwood is being measured. Green logs may have a moisture content ranging from about 20% to 90% (the oven-dry method of measuring MC).
One type of air-dried log is “dead standing,” which refers to trees which have died from natural causes (bug kill, virus, fire etc.) and cut down after they died. Standing dead trees may be cut one month or several decades after they died, so the term “dead standing” does not necessarily mean the logs have dried down to equilibrium moisture content. Dead standing logs can be green, or more-or-less dry.
After construction, green logs dry in service in the log building. Within about four years, green logs which are part of a completed log house reach equilibrium with local conditions and have an equilibrium moisture content (EMC) of between 6% and 12%. The actual EMC varies with local climate, season and location.