Canadian Forest Service Publications
Machine stress rated (MSR) lumber grade recovery of post mountain pine beetle wood. 2005. Lum, C. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC. Mountain Pine Beetle Initiative Working Paper 2005-21. 20 p.
Available from: Pacific Forestry Centre
Catalog ID: 25685
CFS Availability: PDF (download)
A sample of mountain pine beetle (MPB) attacked wood from a drying study was tested to estimate the recovery of typical grades of machine stress rated (MSR) lumber. The MSR lumber recovery was simulated from the test results and visual quality of 1536 pieces of lodgepole pine. Each piece was visually graded and tested for edgewise-bending strength, edgewise-bending modulus of elasticity, and modulus of elasticity in transverse vibration. The amount of bluestain covering each piece was also noted.
Results from three common MSR lumber grade combinations (2400f-2.0E/2100f-1.8E/1650f-1.5E, 2100f-1.8E/1650f-1.5E, and 1650f-1.5E) are presented. Although the sample represents only the lumber from one mill at a point in time, the results support previous findings that the presence of bluestain has no impact on the mechanical properties of lumber.