KEY ISSUES: TIMBER TECHNICAL SUPPORT
Structural pine grading
A3P has announced that it will not proceed with the introduction of Structural Pine (SP) grading as previously planned.
Continuing contact with A3P members, timber merchants, truss and frame fabricators, designers and specifiers has indicated the introduction cannot be achieved without major disruption and unacceptable burden to industry.
As the peak body representing the plantation products and paper industry, A3P acts on behalf of our members, our stakeholders and our industry. The general consensus amongst our members is that the time is not right for the product range to deliver the expected ‘bigger picture’ benefits and therefore it is in the best interests of all parties concerned that we make our intentions clear.
A3P will however, continue to encourage industry adoption of the many valuable outputs obtained from the two year MGP-SP grades R&D program supported by Forest and Wood Products Australia. Many A3P member mills have already implemented upgraded quality assurance procedures as a result of this program.
As part of this work A3P member companies, recently considered the introduction of an MGP grade lower than MGP10. After detailed assessment of the various resource, production and market considerations a decision was recently taken to remain with the current three grade MGP system.
Concurrent with this ongoing work, A3P member companies are concentrating on ensuring that all structural products are adequately assessed with respect to structural property compliance and that such products will be supplied to the market certified fit for purpose under the PTC program – as indicated by the PTC logo on these products.
A3P is determined to ensure maximum benefit is derived from the valuable work completed to date and have a substantial task ahead to deliver the potential benefits in a way that will be acceptable to all parties.
For further information contact the A3P advisory service on 1800 00 PINE.
Technical papers and reports
New SP Grades
Structural Pine Grading – Overview Adobe PDF | 0.1MB
Following the previous A3P Board decision to develop and promote a new set of four grades for structural pine products the A3P Board ratified, at its meeting on 1 March 2006, the design properties and associated design values for the new grades which are to be designated SP1, SP2, SP3 and SP4.
Structural Pine Grading - Design Properties for new SP Grades Adobe PDF | 0.1MB
Technical data
Structural Pine Grading - Draft Technology Transfer Plan Adobe PDF | 0.3 MB
FWPRDC (2004)
This is a technology transfer plan for implementing revised and upgraded pine grading technology into the market and appropriately informing and advising targeted sectors of the building and related industries. This plan has been produced in conjunction with the A3P Solid Wood Marketing Committee and related technical committee.
Machine Grading of Lumber
Machine Grading of Lumber: American Policy Adobe PDF | 0.1MB
American Lumber Standard Committee (1998)
This policy outlines the criteria for approval of machines used for machine grading; criteria for accreditation of an agency; qualification procedures of a mill or facility by the agency; and agency requirements for mill quality control
Machine Grading of Lumber: Procedures under the American Lumber Standard Adobe PDF | 0.1MB
William Galligan and Donald DeVisser
Powerpoint presentation
Machine Grading of Lumber: Producers under the American Lumber Standard Adobe PDF | 0.1MB
William Galligan and Donald Devisser
Increased interest in the export of machine graded lumber from Europe to the United States has required European lumber producers to address the requirements of the American Softwood Lumber Standard (ALS). Grade selection, grade qualification, quality control and process control settings are all mill-specific and test-based..
Machine Grading of Lumber: Practical Concerns For Lumber Producers Adobe PDF | 512kb
William L. Galligan and Kent A. McDonald, US Department of Agriculture (2000)
This report seeks to document such guidelines so that lumber mills can determine the feasibility of machine grading for their products. The first part of this report discusses the principles of using machine grading to assign properties. In the second part, the methods of machine-graded lumber yield assessment are described by an industry specialist. The final part discusses mill mechanical analysis and cost analysis.
Machine Stress Graded Timber
Machine Stress Graded Timber: Effects of Different Manufacturing Strategies Adobe PDF | 0.3MB
Richard Hunt, Justin Ralston, P Simperingham
In this paper, the results of Monte Carlo simulations of different manufacturing strategies are presented along with the
results of experimental testing carried out to verify the simulations. The effects of different manufacturing strategies on the properties are shown depend on a numbers of factors, which include removal rate of higher grade material. It is also shown that the only minor differences occur at the lower bounds of strength and stiffness with significant differences occurring at the mean and higher bound levels.
Machine Stress Graded Timber: Stress Grades and Design Properties Adobe PDF | 0.3MB
David E. Kretschmann and David W. Green
This chapter briefly discusses the U.S. Department of Commerce American Softwood Lumber Standard PS20 (1994) sorting criteria for two stress-grading methods, and the philosophy of how properties for engineering design are derived.
Machine Stress Graded Timber: Tension-Bending Ratios Adobe PDF | 0.2KB
West Coast Lumber Inspection Bureau (2004)
This study suggests that 1), the traditional assigned Ft/Fb ratios may not adequately represent a grade qualified by test of only one strength property and, 2), the use of the ASTM D1990 default tension/bending ratio of 0.45 would be appropriate if only bending tests were conducted and tensile values assigned by default. Conversely, the D1990 default value of 1.2 could be used for machine grades if only the tensile values was determined by test and the bending value assigned by default.
Other reports
Evolution of Standardised Procedures Lumber Change in Moisture Adobe PDF | 0.6MB
US Department of Agriculture (2001)
This paper documents the development of procedures in American Society for Testing and Materials standards for adjusting the allowable properties of lumber for changes in moisture content.
Local and Global Modulus of Elasticity in Wooden Boards Adobe PDF | 0.2MB
Simon Aicher, Lilian Hofflin and Wolfgang Behrens (2002)
This paper reports on an efficient method for determination of the local modulus of elasticity by means of elongation/strain measurements. Further, the effect of local weak sections on the global modulus of elasticity determined by deflection measurement is revealed.
Statistical Analysis of Data for Timber Strengths Adobe PDF | 0.2MB
John Dalsgaard Sørensen and Preben Hoffmeyer
This report describes statistical analyses performed for material strength parameters from specimens of structural timber. Non-parametric statistical analysis and fits to the following distribution types have been investigated: normal; lognormal; 2 parameter Weibull; 3-parameter Weibull
Variability in strength and stiffness of structural Norway spruce timber - influence of raw material parameters Adobe PDF | 0.2MB
Johansson, Marie; Kliger, Robert
Tests to failure in accordance with the European Standard EN408 have been conducted on approximately 750 battens sawn from 12 different dimensions from 23 different stands (Sweden, Finland and France). The main objective of this test was to determine the mechanical properties of sawn wood in terms of the modulus of elasticity Em and bending strength fm.
Timber Information
Free technical information on the source, selection, properties and other atributes of plantation timber based products available for use in building and construction applications.