Abstract
A study was conducted to establish the engineering properties and the influence of knot area ratio (KAR)-based grading rules on the bending strength properties of full-size Canadian Douglas fir timber used in Japanese post and beam building construction. In-grade tests were conducted on lumber selected at random from coastal mills in British Columbia, Canada, that manufacture products for the Japanese post and beam housing market. Bending strength and modulus of elasticity test results and KAR-based out-turn information on the 105 × 105 mm and 45 × 105 mm specimens are presented in this article. The in-grade test results indicate that KAR-based grading rules can be successfully applied to Canadian Douglas fir timber to meet strength property requirements.
Article PDF
Similar content being viewed by others
Author information
Authors and Affiliations
Corresponding author
About this article
Cite this article
Lam, F., Barrett, J. & Nakajima, S. Influence of knot area ratio on the bending strength of Canadian Douglas fir timber used in Japanese post and beam housing. J Wood Sci 51, 18–25 (2005). https://doi.org/10.1007/s10086-003-0619-6
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s10086-003-0619-6