Maybe you have heard of the term “green lumber” before but don’t really know what it is. Green lumber, or wet lumber as it is also known is, as the name suggests, wood used in construction that has a higher moisture content.
When a tree is freshly cut it naturally contains a lot of water. The water that has collected in the woods cells is known by the term ‘free water’. After the tree is cut, this water will slowly evaporate until it has the same level of water content as its surroundings. This is known as equilibrium moisture content, or EMC.
It stands to reason then that the longer this wood is left before being used, the better it dries out and then be good for use in construction, but this is not what always happens with green lumber. After it has been processed, the wood is often kept in plastic wrapping until its ready to be used. This hinders the evaporation process which then means that the wood will still have a higher moisture content when it is used.
Hotter, drier parts of the country such as Arizona and areas of California will often use this type of wood. This is because the wood will dry out quicker.
The reason green lumber is also used is because it generally costs less and is a softer wood, enabling it to be easier to cut and put nails into without it splitting.
We might ask then, is green lumber a better option than kiln dried wood? We will discuss this in a future article.