The extensive outbreak of mountain pine beetle in north central British Columbia is resulting in a large volume of lodgepole pine coming into the log supply for sawmills. The major defining characteristic of beetle-infested trees is the bluestained sapwood caused by fungi carried by the beetle. Because bluestained wood is not very familiar to some consumers, this wood may pose a marketing challenge. Although the non-appearance properties of bluestained wood are widely recognised by the industry as not being compromised, there are no data to support this belief. The literature on other types of bluestained wood reports up to 30% lower impact bending strength (toughness) and higher permeability than for non-bluestained wood.
Forintek Canada Corp. scientists identified the need to generate data on some properties of beetle-killed wood in order to address potential concerns. Approximately 270 pieces each of bluestained lodgepole pine lumber cut from beetle-attacked trees, and equivalent non-bluestained lumber were collected from 14 different sawmills in the B.C. Interior. This was delivered to the Forintek Vancouver laboratory for conditioning and processing into test specimens. The specimens were allocated, in equal proportion from each mill, between tests of mechanical, dimensional stability/permeability, gluing, and finishing properties. The results are presented here and in three associated reports.
This is the first compilation of work on the properties of beetle-transmitted bluestained wood. Overall, the research indicates that this wood can be used, without compromising performance, for structural, furniture, and preservative-treated end uses.
A factsheet summarizing the findings produced for customers of bluestained wood is included in the appendix to this report.