DOST-FPRDI formulates lumber stress grades

LOS BAÑOS, Laguna – Lumber stress grades have been developed by government researchers here.

The grades were formulated under a project titled "Development and Implementation of Lumber Stress Grading Rules for Tropical Timber in the Philippines," funded by the International Tropical Timber Organization (ITTO), a trade association composed of countries producing and consuming tropical timber.

The project was implemented by the Los Baños-based Department of Science and Technology-Forest Products Research and Development Institute (DOST-FPRDI) headed by Director Florence Soriano.

The lumber stress grading (LSG) framework developed by FPRDI will be evaluated and commented on at the "International Workshop on the Development and Implementation of Stress Grading Rules: Philippine Experience" to be held at the Astoria Hotel in Pasig City on Nov. 19-21.

The ITTO-sponsored workshop will be attended by participants from Brazil, Cambodia, Indonesia, Japan, Korea, Malaysia, Myanmar, Papua New Guinea, the Philippines, Thailand, Vanuatu, Australia, and the United States.

Each participant will also present the status and prospects of LSG in their respective countries.

Aside from the LSG framework, a system for machine grading lumber based on full-size testing of lumber has also been developed and piloted.

The workshop organizers stressed that throughout the three main tropical timber-producing regions – Southeast Asia, South America, and Africa – there is a need to develop uniform grading rules that will promote confidence and use of tropical timber for construction applications.

"Efficient use of tropical hardwoods in construction requires an understanding of the structure behavior of numerous species and species groups," they said. "Owing to large inherent variation in mechanical properties, control of properties of wood products through stress grading is an absolute necessity."

Topics to be discussed during the three-day workshop are stress grading concepts; formulating a project to development and implement LSG rules; experimental design and testing program to establish lumber stress grades; integrating the machine grading activity in the mill; formulation of a national LSG standard; economics of a marketing program for machine grading; design and construction using machine-graded lumber; establishing training and information dissemination program; implications of machine-graded lumber (national policies and education); and transition from R&D to industry.