Fences, hardwood floors, and houses all utilize boards to be built. Below is the process of how trees are turned into material that can be easily used.
Trees are cut down and sectioned into logs for transportation. Logs are brought to the facility and sorted by species and grade goal. A laser is used to measure the log and calculate how many boards can be made out of one log to reduce waste. The goal is always to utilize as much of the log as possible to reduce “waste”.
Logs first get loaded and sent to a debarking machine. The log slowly rotates as blades chip away at the bark until the log surface is clean and smooth. The log will then be squared off at the biggest possible size. After being square off, the log is then known as a “cant”. Cants are examined for knots, defects, and size. From this point, the cant will be cut into boards.
Once boards have been measured and cut, they are rung through an edger. This machine trims off any excess wood and cleanly squares off the board. Boards are then run through another machine which cuts them to their proper length.
Boards are then sent on to be graded based on wood species, size and quality. The grading scale is maintained by the National Hardwood Lumber Association. Grades are based on actual measurements from the wood to ensure they maintain consistency. Various grades determine what wood can be used for building, flooring, furniture, etc.
Depending on the sawmill, boards can be sold from this point as “green” lumber, meaning they still contain moisture. Green lumber is typically used for outdoor projects. As the wood dries out, it often leads to cracks or splits, which want to be avoided for construction.
The sawmill could also choose to kiln dry the wood. Boards are place inside of a large building where they are able to dry slowly and evenly to prevent cracking. This process also kills any insects that may have been hiding in the wood.
There is never “wasted product” at a sawmill either. The sawdust created by cuts, bark that came off the log, or any wood chips created are all utilized. Sometimes, the facility is able to recycle the wood into energy for their machines. Otherwise, it can be sold to be used as products for composting or gardening.
“The Basics of Hardwood Lumber Grades.” Woodworkers Resource
“What Happens at a Lumbermill.” Allsands
“What Happens at a Sawmill.” Allegheny Mountain Hardwood Flooring
“Wood Products.” VT.edu