Q. We have some trees in our neighborhood and throughout the city that came down during the recent hurricane. It seems a shame to let these go to the clean-up piles that are sent to the dump. Are there any issues with using these trees for lumber?
A. It is indeed disturbing to see the number of trees that are seemingly wasted after a hurricane or severe storm. When considering using these trees for lumber manufacturing, there are three large concerns.
First, due to the warm weather, the conditions are ideal for the growth of staining fungi (sometimes called sap stain or blue stain) in the trees and logs. Therefore, prompt (often within a week) harvesting and sawing is required. With all the urgent concerns after a storm, spending time harvesting trees and sawing is not a high priority. So, with the likely delay in processing in warm weather, the bottom line is that the lumber that will eventually be produced from storm damaged trees is usually stained.
The second major concern is that trees grown in cities and not in a forest will have several quality and processing issues. Such trees often have metal in them (nails, metal fencing, staples) that will ruin a saw blade. Such trees also have large branches and this means that the lumber produces will be full of stress and will not dry flat.
Such trees often have root damage while growing and develop a bacterial infection that results in wetwood with obnoxious doors and reduced strength. A small shop may be able to work with such lumber sometimes and the resulting defects, but most operations cannot afford to work with this lower quality raw material.
A third concern is that if the trees are not promptly harvested and the logs promptly sawn, it is likely that the logs will start to dry and develop large cracks, both in the ends and on the faces. Sawing logs with cracks is often considered a safety risk. Further, lumber with cracks is not worth much. Some sawmills do have water sprinklers and use end coating on the log ends to reduce this cracking during log storage, but such actions must be initiated promptly after harvest.
Gene Wengert, “The Wood Doctor” has been training people in efficient use of wood for 35 years. He is extension specialist emeritus at the University of Wisconsin-Madison.
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