We believe that two to five years out, we could be seeing this grow from just 20% of our business to potentially 60% of our business, said Redfield, D.R. Johnsons chief operating officer. Were seeing some major growth factors.
From Maine to Arkansas to the Pacific Northwest, the material is sparking interest among architects, engineers and researchers. Many say it could infuse struggling forest communities like Riddle with new economic growth while reducing the carbon footprint of urban construction with a renewable building material. Visually blemished wood that currently goes to waste can be used in the middle layers of a CLT panel without sacrificing strength or look. Supporters say it could bring sawmills back online while improving forest health through thinning dense stands and making use of low-value wood and local tree species. Trees as small as 5 inches in diameter at the top and those damaged by pests and wildfire are prime candidates.
But challenges remain before CLT becomes as common in the United States as it is in Europe and Canada, and not all builders are sold. US building codes generally place height limits on all-wood buildings for safety reasons, though a special committee of the International Code Council is investigating potential changes to address the use of CLT in such structures. And research is still underway on critical questions of how these buildings withstand fire and earthquakes in high-seismic regions. Building codes in Oregon allow cutting-edge designs using new technology like CLT in some cases, but only after rigorous testing and an intensive approval process. That can make such projects cost-prohibitive, said Peter Dusicka, an engineering professor at Portland State University whos been researching the strength of CLT panels. The early adopters are looking at it and seeing it as a good opportunity, but before CLT can take off, there will have to be more examples to get people excited and more mills producing it, said Thomas DeLuca, professor and director of University of Washingtons School of Environmental and Forest Sciences. SmartLam in Montana is the other company producing CLT panels.
This spring, cross-laminated timber will get its ultimate test in the United States when a Portland architectural firm breaks ground on a 12-story wood building in the citys trendy Pearl District. It would be the tallest all-wood building in the world constructed in a seismic zone and the tallest all-wood building in North America. An all-wood building in Norway is taller, but is not in a seismic zone. An 18-story wood building in British Columbia is also taller, but rests on a traditional concrete core. Lever Architecture is using $1.5 million it won in a tall wood building competition sponsored by the U.S. Department of Agriculture and the softwood industry thats intended to promote CLT as a domestic building material. A 10-story residential tower in New York City also got $1.5 million.
The Portland firm has been working with scientists at Portland State University and Oregon State University to test the panels strength by subjecting them to hundreds of thousands of pounds of pressure. They are also testing various methods for joining the massive panels together. Were looking at creating a resilient design, a design that could withstand a major earthquakebasically the earthquake that we all worry aboutand be repaired, said Thomas Robinson, founder of Lever Architecture. The results of the structural testing in Oregon will be made public for other US designers, bringing the material one step closer to the mainstream, Dusicka said.
Back in Riddle, a tiny town tucked in the mist-shrouded forests of Douglas County, Redfield is once more excited about timber in a place where logging used to be king. The 125-employee company has been inundated with visitors from around the country interested in touring their new CLT business expansion. Watching as layers of beams whirred through a glue machine, Redfield said, Were able to take wood that may be turned into chips or pulp and turn it into a product thats pretty exciting.