Funded Research Projects: SUSTAINABLE RESOURCE MANAGEMENT

Thermal Modification of Hemlock Lumber

Research Sponsored By: USDA
Principal Investigator: Ivan Eastin
Project Description
The volume of western hemlock growing on the Olympic Peninsula in Washington State exceeds that of all other timber species. However, markets for hemlock lumber are extremely underdeveloped, partly because drying hemlock lumber is challenging due to the presence of wet pockets and growth stresses in the wood which result in excessive product degrade (e.g., warping and twisting) during kiln drying. The closure of most of the small and medium-sized sawmills on the Olympic Peninsula has left the rural timber-dependent communities in this region reeling economically. Thermally modified (TM) lumber is a relatively new technology that could substantially increase the value of hemlock lumber. The TM process permanently modifies the physical and mechanical properties of the wood so that it has lower water absorption, greater dimensional stability, and increased resistance to insect attack and fungal degradation. Thermally modified wood is therefore well suited to the manufacture of a wide variety of outdoor products. This project will assess the feasibility of the TM process for hemlock lumber and, if successful, will develop a set of prototype product designs. We will also host a TM workshop in conjunction with the Olympic Natural Resources Center. If the TM process is found to be effective with hemlock, this project could provide the foundation for the development of a cluster of small and medium-sized manufacturers on the Olympic Peninsula that produce a variety of complimentary and innovative outdoor wood products using TM hemlock lumber.