A mass movement is underway in Oregon — a mass timber movement.
Mass timber is cross-laminated timber — called CLT — mass plywood and other types of engineered wood that turn lumber into large, strong building materials that can support multi-story buildings. It’s been called “plywood on steroids” and is substantial enough to replace steel and concrete. It’s “green” because it comes from a renewable resource — trees — and sequesters carbon. It also emits less carbon dioxide during its production than other materials.
While mass timber has been used in places like Europe and Australia for decades — huge mass timber structures, buildings and houses have been built across those continents — it’s just starting to catch on in the U.S. That’s because U.S. building codes typically don’t include it.
Now, however, Oregon codes allow its use. National codes could also allow it within a few years, opening the door to wider use of mass timber.
The U.S. mass timber movement had its beginnings in tiny Whitefish, Montana, in 2011, when a 4,863-square-foot commercial building was constructed using CLT. It was completed at a cost of $145 per square foot and took five days to build, according to the Wood Products Council. The CLT panels came from Europe — there are now several sources for it in the U.S. and Canada — and the building was designed using international building codes.
A person doesn’t have to be a construction engineer to see the value of CLT — and the potential of mass timber in general. It is cost-effective, easy to install and strong.
Oregon State University and the University of Oregon have created the TallWood Design Institute to take the lead in mass timber research and development. The U of O College of Design and OSU’s College of Forestry and College of Engineering have a platoon of researchers working on new products and designs, testing materials and helping to chart the future of mass timber.
The institute’s new $79 million building is also made of CLT, though a glitch in its production has set back the construction schedule.
Elsewhere in the state, Freres Lumber Co. in Lyons has patented a new type of mass timber called mass plywood. The company’s owners say the plywood panels can range up to 48-feet long, 12 feet wide and 24 inches thick, use 20 percent less wood and are as strong as CLT.
Other companies in the U.S. and Canada are also pressing ahead with innovations, making the future of mass timber virtually unlimited.
Already in the U.S., buildings as large as 156,000 square feet and eight stories tall have been built in Portland. Seattle allows the use of CLT in buildings up to six stories.
But that’s just the beginning. A 270,000-square-foot mass timber structure is proposed for Chicago, and a 220,000-square-foot seven-story apartment complex is planned for Minneapolis.
And a 100-story mass timber tower has been proposed for London, England.
Now that’s aiming high.