Developing Mass Timber Panels from Small-Diameter Balsam Fir

Worker sprays water onto wood product to prepare for the thermal modification kiln.

An industry partner Composite Recycling Technology Center employee prepares balsam fir materials for commercial-scale thermal modification processing in the kiln. Photo: Matt Aro, NRRI.

About

The Natural Resources Research Institute (NRRI), Washington State University (WSU), and industry partners Mithun, Therma Wood Technologies and the Composite Recycling Technology Center have collaborated to develop high-performance mass timber panels using small-diameter balsam fir. Researchers are thermally modifying and laminating the harvested wood to create durable building panels that are highly resistant to moisture and decay. By demonstrating the performance of this technology from low-value timber, the project aims to offset the costs of wildfire mitigation, reduce forest fuel loads, and boost the competitiveness of the regional forest products industry.

Project Overview

Worker in the forest uses chainsaw to break down balsam fir trees.
A forester removes small diameter balsam fir from a forest in northern Minnesota. Photo University of Minnesota. 

The management of balsam fir stands in Minnesota has become a priority due to an active, long-running spruce budworm outbreak. This native caterpillar feeds heavily on mature balsam fir, leaving behind dense areas of dead, standing wood that elevates regional wildfire risks. Small-diameter balsam fir on National Forest and other regional lands is often not removed. Concurrently, a lack of commercial markets for this material has reduced overall stand management, contributing to an accumulation of forest fuels that elevates regional wildfire risks. This utilization gap is particularly concerning as climate change increases insect epidemics and disease, leaving vast stands of dead, highly flammable wood on the forest floor that acts as a dangerous ladder fuel. To mitigate wildfire risks and improve forest resilience, forestry professionals need high-value, durable products that can utilize this abundant, underutilized wood source.

Shredded balsam fir awaits thermal modification in a kiln.
Balsam fir material loaded into the kiln for thermal modification processing. Image credit: Matt Aro, NRRI.

Researchers are thermally modifying and laminating small-diameter balsam fir to develop high-performance mass timber building panels, evaluate their mechanical strength, fire performance, and resistance to moisture and decay. The team is also completing techno-economic, life cycle, and architectural design assessments to establish preliminary commercial feasibility and connect this restored forest material to the rapidly growing mass timber construction industry. Finally, with support from Mithun, a real-world demonstration of the panels will be completed in downtown Seattle, WA.

Project Goals

Thermally modified balsam fir prepared for mechanical testing. (Image credit: Composite Recycling Technology Center)
Thermally modified balsam fir prepared for mechanical testing. Image credit: Composite Recycling Technology Center.
  1. Develop and engineer durable mass timber panels from small-diameter balsam fir using an optimized thermal modification process.
  2. Assess the structural performance of the new building panels, focusing on their mechanical strength and resistance to moisture, rot, and decay.
  3. Evaluate market viability and applications through techno-economic analyses and architectural design assessments to establish commercial pathways.
  4. Share research findings and market benefits with landowners, timber harvesters, architects, and wood manufacturers to encourage industry adoption.

Outcomes

Finished thermally modified high-performance timber panels. (Image credit: Washington State University)
Finished thermally modified high-performance timber panels. Image credit: Washington State University.

This research aims to deliver comprehensive engineering data on the durability and structural limits of balsam fir mass timber, alongside clear financial and design frameworks for its commercial adoption. By verifying that thermal modification can successfully upgrade low-value wood into premium building panels, the ultimate impact will be the expansion of regional manufacturing opportunities. Cultivating this commercial market provides landowners and forest managers with a self-sustaining financial mechanism to offset the costs of fuel reduction, leading to healthier forest ecosystems and reduced wildfire threats across the region.

Funding

This project is supported by the USDA Forest Service Wood Innovations grant program (grant no. 23-DG-11094200-266) and the National Science Foundation (grant no. 1827434).

Project Team

Matthew Aro, NRRI Research Program Manager

Vikram Yadama, Professor, Washington State University

Omar Espinoza, Associate Professor, University of Minnesota

Craig Curtis, Director of Emerging Building Technology, Mithun

Ryan Rideout, Architect, Mithun

Composite Recycling Technology Center, Port Angeles, WA

Therma Wood Technologies, Ronan, MT

Project Contact

For more information, please contact the project coordinator:

Matt Aro | Office: 218-788-2700 | Email: [email protected]
Natural Resources Research Institute, University of Minnesota
5013 Miller Trunk Highway, Duluth, MN 55811

Research Programs
Sustainable Materials Program
Associated Staff
Matt Aro M.S.