WVFA Mountain State Forestry Fall 2021

F E A T U R E D N E W S 8 West Virginia Forestry Association Mountain State Forestry | Fall 2021 www.wvfa.org Evaluating Low Grade Yellow-Poplar Appearance Graded Lumber as Structural Lumber for Cross Laminated Timber (CLT) Manufacturing By Joseph F. McNeel Professor & Director and Curt C. Hassler Research Professor West Virginia University Appalachian Hardwood Center (WVU AHC) WHEN A BUSINESS CONSIDERS ENTERING A NEW PRODUCT MARKET, there are many factors to be considered in making such an investment. Among these can be the need for a new or reconfigured physical plant to conduct the manufacturing, new pieces of equipment that perform different operations, a different raw material, employees with different competencies, and a revised marketing strategy, among others. This is essentially the situation that hardwood lumber manufacturers face as they contemplate entrance into the CLT (Cross-Laminated Timber) market. These factors all come into play for a hardwood producer considering manufacturing CLT’s for the commercial market. In this situation, the raw material, in the form of lumber, requires close consideration. Softwood Lumber Grading Currently, CLT manufacturers produce panels made from softwood species. This lumber is readily available in the marketplace and can be purchased and placed into the production process with relative ease. The American Softwood Lumber Standard (ASLS) was developed and approved by the American Lumber Standards Committee (ALSC) in accordance with the Procedures for the Development of Voluntary Product Standards of the U.S. Department of Commerce and is the basis upon which softwood lumber is graded. Softwood lumber that is 2 to 4 inches thick, for the most part, is stress graded and assigned structural properties according to the National Grading Rule as part of the ASLS (Wood Handbook, 1999). 1 There are a number of independent organizations that write and publish grading rules, such as the Northeastern Lumber Manufacturers Association (NELMA) in the Northeastern US. There are also a number of independent agencies that provide grading and marking services to the industry. Most of these grading services use visual assessment of the lumber and the associated defects to assign a structural lumber grade to hardwoods. Stress grading is another approach to the structural grading process and can be conducted either visually or mechanically. 1 Forest Products Laboratory. 1999. Wood handbook: Wood as an engineering material. General Technical Report FPL– GTR–113. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 509 pp