How Does A Sawmill Work?

The life of a log is an interesting one.  The process of lumber milling actually starts long before the log ever reaches the mill.

Step 1 - Logging & Transportation - Timber harvesting, or logging, is the first step to getting a log to the sawmill.  Trees are cut down using chainsaws during the logging process.  This step is known as felling.  Felling is essentially cutting down the tree and cutting it to length.  Then, the log is delimbed and loaded on a truck for transportation to the mill.  Once at the mill, the logs are unloaded and stacked into piles where they wait to be cut.

Step 2 - The Log Enters The Sawmill - Next, the log is moved using piece of heavy machinery and put on a belt where it awaits its turn to be cut.

Step 3 - Debarking The Log - Once the log gets to the front of the conveyor belt, it will enter the mill to be debarked.  A debarking machine is used to strip the log of its bark.  The bark is then saved as it can be sold as mulch or used to fuel certain kilns at a sawmill.

Step 4 - Metal Detection - Each log will go through a large metal detector before being cut.  Since trees can live for hundreds of years, there's no saying what could be found in them.  Often you will find nails, wire fencing, or other metals in the logs which can ruin your sawmill blades if they're not caught beforehand.  For the logs that have metal in them, the metal will either be removed or the log will be cut into smaller sections so as much as possible can be salvaged.

Step 5 - Merchandising the Log - Merchandising in the modern age has made sawmills much more efficient.  Lasers can be used to estimate the log so the mill can maximize the lumber it gets from each and every log.  Over the course of days and weeks, this can make mill more profitable by eliminating unnecessary waste on every log that's cut into lumber.

Step 6 - Head Rig Sawing - When you think of a sawmill, you likely picture the head rig.  Logs enter the head rig saw by getting clamped on a conveyor belt where the head rig blades move through the log.

Step 6 - Canting the Logs - The head rig cuts the log into cants, which are essentially logs that are flat on at least one side.  The logs can be sold as cants with only one size milled, but this isn't normally the case.  If the size of the lumber needed is unknown, the business will likely buy cants and cut them to size.  Pallet manufacturers often do this since the pallet sizes are built custom based on the dimensions of the product it's being used for.

Step 7 - Resawing - Cants that enter the resawing stage are usually being milled into rough cut lumber.  The resaw uses multiple bandsaw or gang saw blades to cut the log into the boards that were merchandised in step 5.

Step 8 - Edging the log - In this step, the lumber gets its sides cut.  This squares up the log so that it fits a specific grade or width.

Step 9 - Trimming - The trimmer is used next to cut the lumber to length.  The length will vary based on the order or lumber size we're trying to accomplish.  We manufacture lumber that is up to 50 feet long.

Step 10 - Grading the Lumber - The actual milling process is now complete and the lumber is ready to be graded.  This is essentially a process for quality control.  Since most sawmills won't plane lumber and only sell rough cut, the grade is usually known as "FAS".  The used to grade lumber as first and second grade, but have since combined the two to make FAS.

Step 11 - Drying - Many sawmills don't use a kiln and will just let their lumber air dry.  Others buy kilns which can speed up the drying process significantly and increase the value of the lumber.