We have always been blessed to have the species and quality of timber that we do in our region (Pennsylvania, New York, and West Virginia). You’ve probably heard many times over how some of the very best hardwood species in the world (i.e. black cherry, hard maple, red oak, etc.) specifically grow very well here due to the climatic and physiographic conditions we enjoy. We have benefitted from both domestic and international demand for these sought-after species for many decades, and though we’ve certainly seen market demand fluctuate over time, consumers all over the world continue to enjoy products that are made from these hardwoods.
However, it’s always good to look for ways to expand our hardwood markets, as healthy demand keeps the values/prices for our quality timber products at beneficial levels. And despite the dual markets we have, we’ve certainly seen times when the desire for or the ability to purchase our quality hardwood resources drops a bit. Finding other uses for our resource beyond the traditional sawtimber/pulpwood markets would add extra layers of stability, which has long been the goal of researchers, consultants, industry and certainly forest landowners. Universities and Industry Associations are constantly exploring other uses for our hardwoods that would benefit society as well as the landowner who must support the land on which these forests grow.
Obviously, traditional wood products like wall studs, joists, trusses and plywood have been more than adequate to build multi-storied houses for hundreds of years now. Several years back we started hearing about technologies that were being developed to engineer wood products into building materials that to a large degree would rival the structural capabilities of concrete and steel. This would allow for these products (known as cross-laminated timber (CLT), or mass timber products) to be used for high-rise residential and office complexes where steel and concrete often had sole ownership of that domain.
ThinkWood.com is an informational outlet sponsored primarily by the Softwood Lumber Board (SLB), along with help from the Wood Works-Wood Products Council, the American Wood Council, the Northeastern Lumber Manufacturers Association, the Southern Forest Products Association, and several Western-centric Lumber Associations coming together to promote the demand for CLT products in outdoor, residential and non-residential construction. Their website nicely explains CLT in simple terms:
“Cross-laminated timber (CLT) is a wood panel system that is gaining in popularity in the U.S. after being widely adopted in Europe. CLT is the basis of the tall wood movement, as the material’s high strength, dimensional stability and rigidity allow it to be used in mid- and high-rise construction. CLT panels are made of layers of lumber boards (usually three, five or seven) stacked crosswise at 90-degree angles and glued into place. The panels can be manufactured at custom dimensions, though transportation restrictions dictate their length.
“Applications for CLT include floors, walls and roofing. The panels’ ability to resist high racking and compressive forces makes them especially cost-effective for multistory and long-span diaphragm applications. Some specifiers view CLT as interchangeable with other wood products and building systems. Like other mass timber products, CLT can be used in hybrid applications with materials such as concrete and steel. It can also be used as a prefabricated building component, accelerating construction timelines. Several factors contribute to a growing market for CLT and tall wood construction: advances in wood connectors, the development of hybrid materials and building systems, the commercialization of CLT and growth in off-site fabrication.
“Alternating grains improve CLT panels’ dimensional stability. The lumber boards typically vary in thickness from 5/8 inch to 2 inches and in width from 2.4 inches to 9.5 inches. Finger joints and structural adhesive connect the boards. In structural systems, such as walls, floors and roofs, CLT panels serve as load-bearing elements. As such, in wall applications, the lumber used in the outer layers of a CLT panel is typically oriented vertically so its fibers run parallel to gravity loads, maximizing the wall’s vertical load capacity. In floor and roof applications, the lumber used in the outer layers is oriented so its fibers are parallel to the direction of the span.
“CLT’s ability to resist high racking and compressive forces makes it a cost-effective solution for multistory and long-span diaphragm applications. CLT’s shear strength affords designers a host of new uses for wood. Those include wide prefabricated floor slabs, single-level walls and taller floor plate heights. As with other mass timber products, CLT can be left exposed in building interiors, offering additional aesthetic attributes.
“Currently, U.S. building codes do not explicitly recognize mass timber systems, but this doesn’t prohibit their use under alternative method provisions. The 2015 International Building Code (IBC) streamlines the acceptance of CLT buildings, recognizing CLT products when they are manufactured according to the Standard, ANSI/APA PRG-320: Standard for Performance Rated Cross Laminated Timber. In addition, CLT walls and floors may be permitted in all types of combustible construction, including Type IV buildings.”
Recently, FORECON attended the annual Forest Landowner’s Association Conference, held this year on Lake Oconee in Greensboro, GA. One of the featured speakers was Dr. Richard Vlosky, the Director of the Louisiana Forest Products Development Center at the LSU Agricultural Center. Dr. Vlosky’s talk focused on the viability of CLT wood products in the marketplace, and the recent accomplishments that have been made concerning its acceptance and use as a significant building component for larger residential and industrial structures. Among a lot of interesting statistics, Dr. Vlosky mentioned that CLT production is increasing at a rate of about 16% per year at the moment and is expected to top $2.5 billion in sales by 2025. There are currently over 600 buildings primarily made using CLT products in the U.K. already, and we are starting to see the increased use of CLT in the Pacific Northwest.
When asked about its abilities to withstand both fire and seismic testing, Dr. Vlosky said that CLT responded very well – it is extremely difficult for CLT lumber to continue burning once ignited, and tests show that if covered with gypsum board, it is virtually “fireproof.” Also, because of the inherent flexibility in the fibers of the wood, CLT responds better that concrete or steel during earthquakes as it has more “give” to it!
Lastly, since it is primarily a product currently manufactured out of softwood lumber, we had the chance to ask about the role that hardwoods may have in the future of CLT. Apparently, projects are already underway to bring hardwood species into the mix for two main reasons; first, the use of hardwoods would substantially expand the resource pool going forward, and 2) the fiber of some hardwood species is ideal for increasing the structural strength of the finished product. Besides the increased market opportunity in general, the hardwood material used in this process would generally be low-grade wood (grade 3 or worse) that typically goes into making pallets and cants. It is thought that the use of this low-grade material in CLT products will result in an increase in its value and consequent price.
FORECON is very interested in tracking the use of CLT in various construction activities both domestically and internationally and is especially interested in the part that hardwoods can play in this new industry. We are grateful to be a “Project Partner” in helping support Dr. Vlsoky and LSU in their on-going research into the markets developing for forest landowners concerning CLT. It is our hope that not only will CLT become the environmentally-friendly “go-to” material for large dimension construction projects in the future, but that our hardwood resource will be part of that opportunity.