The Canadian lumber industry has identified, as a high priority, the establishment of a multi-year Lumber Properties Program that pulls together a number of urgent initiatives currently underway to establish and/or maintain Canadian lumber design values. The desire is to have an overall program that emphasizes the proper development of a longer-term strategic plan and process to deal with current and future initiatives. Combining the current industry resources with Federal Government contributions through Natural Resources Canada (NRCan), the first step in the Program has been completed: to gather the various initiatives now underway and to begin the formal development of pan-Canadian policies to guide the development, implementation and on-going maintenance of such initiatives.
The key activities in 2006-07 were:
Launching of the pilot phase of the on-going monitoring program, and development of a simulation model to assist in determining what sort of trends can be reliably detected and which cannot;
Completion of the in-grade testing program on Canadian Norway spruce;
Analysis of the No.2 2x4 Hem-Fir (N) monitoring study and confirmation of the appropriateness of assigned design values;
Identification of an alternative species grouping procedure for further study;
Starting of a process under the ASTM Committee on Wood to address gaps in the Grade Quality Index provisions in ASTM Practice D1990, and
Establishing a forum for engaging the US in discussions on lumber properties issues.
Lumber properties issues crucial to maintaining the competitiveness of Canadian lumber continue to be the same as in previous years: tests and means to adjust for sample representativeness using the Grade Quality Index (GQI), species grouping and re-grouping procedures, and on-going lumber monitoring. As a result, discussion on a pan-Canadian strategy and supporting policies necessary to support Canadian lumber initiatives tend to focus on these three issues. The challenge is to ensure that these issues are dealt with in a way that balances both short and longer-term needs and provides a net overall benefit to the Canadian industry.
Industrial heat treatment technology for wood has been under development since the 1970s. The technology consists in heating wood to temperatures of from 150°C to 240°C while preventing it from burning. This is achieved by heating the wood in either an inert atmosphere or saturated vapour environment. Heating the wood over 200°C changes the chemical structure of the wood and results in a reduction in its hydrophilic behaviour. After heat treatment when wood colour has changed to brown, an improvement in dimensional stability and biological durability should be observed. However, some mechanical properties of the wood may have decreased. This enhanced dimensional stability and biological durability make heat treatment an interesting option for the protection of wood used in exterior applications. The objectives of this study are to assess the performance of heat treatment technologies and to determine the properties of jack pine and balsam fir after heat treatment, as regards to exterior applications. Owing to difficulties in the start-up period that significantly delayed the project, no experimental work had been conducted by the end of March 2003. The lumber has however been sent to two companies for treatment and the physical and mechanical tests will be conducted under a new project entitled “Quality Control and Certification of Thermally Modified Wood.” A final report will be issued at the end of March 2004.
The basic wood properties of 45-year-old second-growth sitka spruce were examined to determine if rapid growth produces poor wood quality. Five dominant and codominant trees were sampled from each of four stands with stocking densities of 520, 640, 1080, and 1520 stems/ha. Stem size, extent of live crown, yearly wood relative density trends, and longitudinal shrinkage were measured.
Higher bearing strength values for Hem-Fir, where justified, will allow designers to realise the full strength potential of the lumber. Machine stress rated (MSR) lumber would benefit the most from an increase in the Hem-Fir bearing strength. Although there are few Hem-Fir MSR lumber producers, it is anticipated that given the recent or planned increase in installed kiln capacity on the west coast, more mills will be considering producing MSR lumber. Acceptance of Hem-Fir MSR lumber in the marketplace will depend on the design values assigned to Hem-Fir MSR lumber. The objective of this project is to establish characteristic bearing strength values for the Hem-Fir species group in CSA O86.1 and progress to date is described.
The purpose of this small study was to examine the effect of various test methods upon the bending moduli of elasticity and to determine the bending strength of selected Douglas-fir and spruce laminated veneer lumber specimens.
In order to provide bridge designers with better information, International Forest Products Limited (Interfor) asked the Forest Engineering Resarach Institute of Canada (FERIC) to evaluate the bending strength and stiffness of log stringers used for constructing bridges on forest roads in coastal British Columbia. Given the lack of definitive standards for testing this material, FERIC developed a field-based test procedure and designed a test facility for destructive testing of full-size, whole-log stringers obtained from second-growth stands. Sixteen coastal Douglas-fir and twelve western hemlock logs were tested in 2003. This report describes the test procedure and methods of analysis, presents the log bending strength and stiffness results, and makes recommendations regarding future testing.
