Standing Dead Timber Facts

Some Facts About Standing Dead Timber What's the best type of wood to use for building log homes? This is one of the most frequently asked questions posed by prospective log home customers. It used to be that those wood species that were naturally resistant to insects and decay were the most desirable wood species but since the invention of borate-based wood treatments, any wood species can be impregnated with enough borate to protect the wood from wood destroying organisms like insects and decay fungi. In fact, borate treated wood lasts longer than the best naturally resistant wood species. So the answer to our question about the best type of wood to use is dry wood. What is the definition of dry wood? Typically we consider any wood with an overall moisture content of less than 20 percent as being dry. By this we mean that if we measure the moisture content of a log at any location across it's entire cross section the moisture content will not exceed 20 percent.

So how can you get logs that contain less than 20% moisture? There are essentially two methods of drying wood, air drying or kiln drying. When a live tree is harvested it can contain up to 200% water by weight. That is if a green log weighs 300 pounds the same log will weigh 100 pounds if dried to zero percent moisture content (virtually impossible to do). Even in a hot kiln it may take many days to drive most of the water out of a 10 inch diameter log and it can take a year or more for a similar log to air dry to below 20% moisture content. But what if you could find dead trees that have been air drying for many years? Wouldn't they make great logs for building log homes? Actually standing dead timber is one of the best sources of dry logs and there are literally thousands of acres of standing dead timber in North America that can be used for constructing log homes. However, very few log home companies make the effort to harvest these trees since the cost is typically higher than cutting down local live trees and transporting them to the mill.

So what killed these standing dead trees? Most were killed by bark beetles. Over the years there have been several widespread infestations of pine bark beetles that killed whole forests of trees. Once the trees died the beetles moved on and left the dead trees behind. Is there a risk that the dead trees are still infested with the beetles that killed them? None at all. There are hundreds of varieties of beetles that infest live trees but only a very few that infest dead, seasoned wood. And even most of these prefer wood with a moisture content above 20 percent.

The only negative aspect to the use of beetle killed trees is the tracks and holes left by the beetles while they were active in the live tree.

Tracks In Log Made By Bark Beetles But these are just visual imperfections and have no effect on the strength or structural integrity of the logs themselves. Beetle killed, standing dead timber is one of the best sources of high quality dry logs available in the world and although harvesting them is somewhat expensive, if left untouched these dead trees will eventually succumb to fire or decay. So not only do standing dead timber logs make excellent log homes, they are one of the most environmentally responsible ways to use a natural resource that would otherwise go to waste.

Vincent R. Palmere Executive Director NovaGuard Technologies, Inc.