American Log Homes, Inc. has utilized dead standing lodgepole pine and Engelmann spruce in its homes for over thirty years. Besides the obvious reason of using a resource that would go to waste there are several other reasons why it is a good choice.
The lodgepole pine, as well as spruce, is soft and thus easy to mill and install using a variety of fasteners. Because of their cellular structure, they also have an “R” factor which is conducive to a well insulated home. However, let it be known that a well insulated log home is not just a matter of a high “R” factor. “R” factor does not take into effect air leakage of a home. To build a good, energy efficient home one must build a tight home whether it is a log home or a conventional “stick” framed home. This is where the issue of dry wood comes into the fore.
The dead standing pine dries out naturally in the forest prior to harvest. Depending on the length of time that it was standing dead in the forest will determine how dry it is. Thus after logging and having the timers sawn into a usable form of milling, the timbers must be checked individually for moisture content. The trees within any particular logging sale may have died over a period of years. Some trees can be very dry and others can be very wet.
At American Log Homes, Inc. a moisture content of 15% or less is required for all manufactured products. This prevents the problems of shrinkage, twisting and warping. It also allows the employees to cut out any large seasoning cracks or other imperfections resulting from the drying process. Many of those who are not versed in wood technology feel that shrinkage is the only factor that one must be concerned with during the drying cycle. This is far from the truth! Twisting, warping, cupping, cracking and splitting is also a result. These defects can be dealt with after drying is complete and during the manufacturing process. All of these defects do not occur on each log or any high proportion of the logs that are dried, but when it does they can be dealt with at the plant and not in the field during construction.
What about insect borings and “bug holes” as some people refer to the tunnels built into wood by uninvited insects? The mountain pine beetle only bores through the exterior of the tree trunk. These larval tunnels are then removed when the log is cut into lumber or timbers at the sawmill during primary processing. Other boring holes can be found as created by the long-horned beetle but the vast majority of these are removed during the sawing and milling process. The insect life cycle can be a matter of 6 months or some a matter of a few years. When the life cycle is completed the larva exit the tree as an adult insect and never come back. Remember, these insects infest live trees and not dead, dry trees! In the many years (30) that American Log Homes, Inc. has been using dead standing lodgepole pine and Engelmann spruce, a problem with living insects in the wood has not been a problem. Not a problem at all.
There are those, who are not foresters or who know little about the complexities of wood who try to scare log home clients into thinking that their log home will be eaten by these wood boring insects. Not so!! A problem can be encountered, however, if one uses green, unseasoned logs with the bark on or only partly removed. Various wood boring insects can then lay their eggs under the remaining bark and cause a problem with incessant sounds of boring as they tunnel into the wood.
Education is always the best answer when one is attempting a project. It is no different with wood and all of its complexities. If you don’t know, ask a unbiased source such as a locals state forester or contact the U.S. Forest Products Laboratory (U.S. Forest Service) in Madison, Wisconsin. They can help you with a number of questions and concerns about wood and its uses. Do this before you start and not after the project is completed. An ounce of prevention is worth a pound of cure!
