Perhaps you have heard the term “green lumber” before but are not sure what it is. Green lumber is also referred to as wet lumber. As the latter name would suggest it is wood with a high moisture content that is used in construction.
As we would expect from a living thing, a freshly cut tree naturally contains a lot of water. The term ‘free water’ is used for water that has collected in the cells of the wood. After the tree has been cut down, this water will gradually evaporate until it reaches the same water content level of its surroundings. This is known as equilibrium moisture content, or EMC.
Obviously then, the longer this wood is left before it is used for construction etc. the dryer it will become, and better for use. This is not the case with green lumber however. After it has been processed, the wood is often stored in plastic wrapping until it is ready for use. This hampers the evaporation process, so the wood still has a higher moisture content when it is used.
Areas such as Arizona and parts of California often use this type of wood for construction as it dries out quicker in hotter places.
The reason green lumber is used comes down to the price. It normally costs less and is a softer wood, making it 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.
Mike McFadden, Certified Master Home Inspector in Orlando, FL