CLT Promises New Construction Boom in the Future, Pilot Programs Under Development in Oregon
Multi-Story Buildings Going Up in Oregon Using cross-laminated timber (CLT).
The use of cross-laminated timber (CLT) in multi-story buildings is no longer just something people are talking about. In Oregon, two new buildings that feature CLT are almost complete, and construction on a much taller 12-story building is set to begin next year.
CLT has been making a lot of headlines lately, as some architects and contractors want to use it to build tall buildings because of its sustainability benefits, especially its ability to store carbon dioxide. CLT is made from long pieces of lumber glued together and then layered perpendicularly to form thick panels which can be as large as 10’ wide and 50’ long.
CLT is six times lighter than concrete, cost competitive with steel and concrete, and fire rated to meet current building codes requiring material to pass a 2-3 hour fire rating.
How might CLT impact the low-grade market? CLT can be made from low-grade lumber. And in the layering effect, CLT reduces the impact of defects, such as knots. Waste wood doesn’t really work though because you need long pieces. CLT works best with as much continuous wood as you can get.
Although hardwood and softwood can both be used to produce CLT, much of the research and development has been done with softwood due to their widespread acceptance in the construction market. In the long run, CLT may become a competitor for wood material for pallets and other industrial applications. But most people believe it could take years for this market to truly develop because building codes and public preferences need to be changed.
Richard Woodcock Education Center
When the Richard Woodcock Education Center officially opens this month at Western Oregon University (WOU), it will be the first multi-story building in the state constructed with CLT. CLT panels were used in limited areas of the two-story structure including the stairwell and around the fireplace.
The $18.6 million building features “creative usage of wood through wood moment frames and timber hybrid structures, and will also promote the use of cross-laminated lumber,” according to Lisa Catto, a WOU media relations spokesperson. It will not only serve as the new College of Education building for the university, but has also been designated as a demonstration project to promote the innovative use of Oregon wood products by former Governor John A. Kitzhaber.
The CLT panels used at the new center were manufactured by D.R. Johnson Wood Innovations, a division of D.R. Johnson Lumber Co. in Riddle, Oregon. In business since 1951, the second-generation, family-owned business is the first U.S. manufacturer of structurally certified CLT (APA/ANSI PRG 302 Certification Standards), according to the company’s sales manager Todd Black.
“Currently we are certified through the American Plywood Association as a V1 Grade CLT Manufacturer, which means we utilize Douglas fir in all our CLT panel production. The typical Douglas fir we use is 25-35 years old,” he said. “Although these panels are very rigid and structurally stable, they are much lighter than their steel and concrete building material counterparts.”
Approximately 3,032 sq. ft. total of CLT was used on the WOU center.
Albina Yard Project
CLT produced by D.R. Johnson is also being used in the Albina Yard Project, a four-story, 16,000-square-foot mixed-use office building in Portland. It is two stories taller than the Woodcock Center and is said to be the first commercial building in the country with a structural system made from domestically produced CLT. The project is on schedule and slated to be completed by the end of this summer, commented Black.
“The CLT panels used in the Albina Yard Project ranged in size from 9’x20’ to10’x22’,” he said. “The CLT arrived on the jobsite completely fabricated and ready to set directly from the truck onto its location within the project. By the third floor, the 4,000+ sq. ft. of floor panels were craned off of the truck and placed on the project in two hours.”
“There were three floors and one roof structure that were approximately 4,000 sq. ft. a piece. Eighty to 85 CLT panels were set on the D.R. Johnson Glulam beam/column structural frame to complete the project. The bottom (ceiling) side of the CLT panels and all Glulam beams/columns will remain exposed while the top side of the CLT panels will have a gypcrete topping slab and traditional flooring material applied,” he explained.
12-Story High-Rise in Portland
A new building being proposed by Framework LLC in the Pearl District in Portland, Oregon, could very well be the tallest building in the country to use CLT when it is completed. The project was one of two projects to win the U.S. Tall Wood Building Competition last fall, and D.R. Johnson is in the running to supply the CLT for its construction.
The 12-story urban building will be constructed primarily with CLT and is currently in the product testing phase. It will include street-level retail, office, workforce housing, and a community space designed to include a public Tall Wood Exhibit, featuring resources related to the realization and design of the building.
“We are very excited at the opportunity of potentially being a materials supplier for the project,” Black proclaimed. “To have a building of this magnitude constructed in Oregon, utilizing mass timber products procured, manufactured and supplied within 200 miles of the project site, would be a special project for us to be involved with and a real spark for the local wood industry as a whole.”
More About D.R. Johnson
The division behind the CLT started in 1967 with glulam production. CLT is now being sold under the name D.R. Johnson Wood Innovations. The glulam business started 16 years after the related sawmill began.
After D.R. Johnson, who started the company, passed away in 2010, his daughters Valerie Johnson and Jodie Westbrooks took over the company. After huge investments in machinery, technology and expansion of their Riddle facility, the company started producing CLT in 2015. It manufactures its CLT using a USNR panel press and Hundegger PBA CNC machine. A pure melamine formaldehyde resin with no urea or urea-formaldehyde additives is used to form the panels.
In addition to its CLT projects, the company has provided Glulam beams and columns for a number of high-profile projects including the Google headquarters in Mountain View; Pixar Studios in Emeryville; Jay Leno Vintage and Classic Car Collection Building in Beverly Hills; and the Portland Trailblazers Practice Facility in Tualatin, Oregon among other notable buildings.
For more information on CLT, visit http://oregonclt.com/.
Published by: Pallet Enterprise
Written by: Lisa Monroe