Through a grant from the U.S. Forest Service, and in conjunction with The Hardwood Manufacturers Association, Appalachian Hardwood Manufacturers, Inc., and the National Hardwood Lumber Association, researchers from Virginia Tech continue to analyze the viability of Yellow Poplar in the manufacture of cross-laminated timber (CLT) panels.
Virginia Tech professors and researchers, Dr. Henry Quesada and Dr. Brian Bond, are directing the project to learn if Poplar CLT is feasible in appearance and structural applications. (Preliminary results indicate that 1COM Poplar can be used for appearance and 2COM Poplar could be used for structural materials.) Additionally:
- In early November, an initial shipment of approximately 10,000 board feet of 2COM and 3COM kiln dried Yellow Poplar was delivered to CLT manufacturer SmartLam, Dothan, Ala., to build and test cross-laminated timber panels. The company will test a variety of glues, volumes of pressure and amount of time needed to press the panels.
- When the tests are complete, the balance of 40,000 board feet of lumber will be graded to Northeast Lumber Manufacturers Association structural standards and shipped. SmartLam will build as many panels as possible, detail the manufacturing process and performance test the products to International Building Code requirements.
- Thus far, CLT has been dominated by softwood species like Douglas Fir and Southern Yellow Pine. The American National Standards Association approved ANSI/APA PRG 320-2012 Standard for Performance-Rated Cross-Laminated Timber and it has been included in the International Building Code.
- This project will take the necessary steps required for Poplar CLT to be included in PRG 320 in 2021. This inclusion could lead to a significant amount of low-grade Poplar lumber being used in this expanding product sector.
The research project is also analyzing the willingness of U.S. hardwood sawmills to produce structural lumber in fixed widths and structural grades, and developing methods to train lumber graders to structurally grade hardwood lumber.
Special thanks to Tom Inman, President of the Appalachian Hardwood Manufacturers, Inc. for providing this update.