Despite the ecological and economic advantages of using cross laminated timber (CLT) products, the North American building industry has been slow to adopt this emerging architectural component. The technology has been used in Europe and British Columbia for over 20 years. Many parts of the world have embraced laminated timber (CLT) and mass timber as components in large scale architectural projects. As cross-laminated timber is emerging across portions of the US, this region is far behind despite the abundance of forest resources and the economic benefits that would be achieved by producing a developing building component. One reason for this is our location in the heart of the central hardwood region, and our forest cover being overwhelmingly hardwood species. Structural grades for hardwood species have existed through the Northeastern lumber manufacturers association (NELMA) which allows for usage with an inspector's assessment and grade stamp as one option. The acceptance of yellow-poplar in PRG-320 provides a pathway for further testing of hardwoods in cross- laminated and nail- laminated products that could be produced locally, thus providing needed markets to landowners for lower grades of logs and lumber of underutilized species to aid in oak regeneration. Oak regeneration, specifically White oak (Quercus alba) is important to support wildlife and Kentucky's $9 billion Bourbon industry.

Leveraging a diverse team across multiple disciplines at the University of Kentucky, including Forestry, Architecture and Civil Engineering; we continue to take a holistic approach in stimulating the production and adoption of CLTs in the Architecture, Construction, and Engineering Industry. Further testing is ongoing with funding from the Kentucky Agriculture Development Fund and industry partnerships. This is part of an ongoing (7 years) awareness, adoption and acceptance program of mass timber specifications and market development to benefit our local communities, forest management and assist industries interested in this developing technology. We have successfully tested hardwood CLT panels under compression and published our results in the Journal of Architectural Engineering.

Link to journal article: Compressive Properties of Cross-Laminated Timber Panels Made of Hardwood Tree Species from the Appalachian Region — Penn State (psu.edu) 

Program impact can lead to changes in how we build structures to use material more intentionally building to store carbon and manage forests. Analysts project that this market will continue to grow rapidly with billions of dollars in economic potential regionally.