Naturally, as we expect from any living organism, a tree that is freshly cut contains a lot of water. Water that has collected in the cells of the wood is referred to as ‘free water.’ When a tree has been cut down, this free water will slowly evaporate until it reaches a water content level that equals its surroundings. This is identified as equilibrium moisture content, or EMC.
It stands to reason then, that the longer the wood is left before it is used in construction etc. the dryer it will be, making it better to use. Green lumber though, is wood that has not been allowed time to dry out in this way. Very often, after processing, the wood is covered in plastic wrapping and stored, which hinders the evaporation process. This means that the wood still contains a higher moisture content when used.
In hotter areas of the country like Arizona and parts of California, this kind of wood is often used, for the obvious reason that it will dry out quicker.
Why is Green Lumber used for construction?
As with most things, it comes down to cost. Green lumber is usually cheaper to use. It’s also easier to use as it is softer, which means nails can be driven into it without it splitting, and also making it easier to cut.
The question could arise then, is Green Lumber a good option to use than say, kiln dried wood? This is something we will consider in our next blog.