Most of our region has experienced extremely dry weather over the past month. The U.S. Forest Service terms the recent dry conditions “episodic drought.” Over the years, most of us have seen weather patterns like those we are experiencing this summer, but we never know from month to month or year to year what the weather will be in Wisconsin. A wet summer can make logging and hauling challenging. A dry summer is a landowner’s, logger’s, and forester’s dream, as production delays are generally limited.
At the mill level, each condition presents challenges. During wet weather, the most obvious challenge for a mill is having enough logs to saw to keep the mill running consistently at scale. Mills rely on consistent production to keep fixed-cost capacity at optimal levels.
Also, a hot, wet summer increases the risk of staining maples, basswood, birch, and other whitewoods. Temperature, moisture, oxygen, and time all influence wood staining. Obviously, muddy ground during a wet summer is the biggest barrier to hauling wood. We have seen instances where the ground was too muddy to haul late in the week. Wood cut on Friday and hauled the following Monday had up to four inches of stain in the ends of the log. This is extreme, but it has happened. Unfortunately, stain is a defect in the lumber market.
During dry summer conditions, mills receive inbound logs, often at a pace faster than they can saw them before stain takes effect in the logs while they are on the log deck at the mill. Dry weather also promotes checking at the ends of the log. This happens because the log dries from the outside in. When the ends of the log dry out, the wood shrinks, and checking appears as small splits at the ends of the log. This also happens where the bark has come off the log during handling, and the log has been exposed to direct sun before it enters the mill. Most of the time, in the case of end checking, these log ends are trimmed off in the mill to prevent further damage to the lumber downstream in the mill process.
There are many ways we work to mitigate the challenges of summer logging. One way is to store logs on shaded landings and mill decks to allow enough airflow to keep moisture from getting trapped between logs on hot days. Additionally, we run a sprinkler system on the log decks. The water from the sprinkler keeps the logs cool enough to delay staining and wet enough to prevent checking on the ends and surfaces of the logs. Along with this, we want to keep the sun off the ends of the logs to prevent them from drying out too fast.
Some of the mitigation measures may seem to contradict what causes staining in the wood. It is a delicate balance. Through trial and error, it appears we have found an acceptable balance among temperature, moisture, oxygen and time to minimize damage to the logs.
In the end, we cannot control the weather when it comes to log handling and storage. However, with proper planning and timing, we can do our best to keep logs fresh and of high quality.
