A 4-foot by 20-foot cross-laminated timber panel in a building under construction at Oregon State University failed earlier this month, prompting the university to hire an outside engineer to investigate but leaving its commitment to the construction technique intact.
The panel fell March 14 after one end delaminated, according to an article in the Gazette-Times in Corvallis, Oregon. The 7 1/2-inch thick panel was made from five layers of 2×6 boards glued up at right angles (see image #2 below). No one was hurt in the incident.
When completed, the three-story, 80,000-square-foot building called Peavy Hall will be the new home of the College of Forestry. The panel was manufactured by D.R. Johnson in Riddle, Oregon, the first fabricator in the country to manufacture cross-laminated timber (CLT) panels certified for structural applications.
Steve Clark, the university’s vice president for marketing and university relations, said by telephone there have been no other problems with CLT panels on the project, and that the university remained “completely committed” to the construction technique.
“It came completely out of the blue,” he said, adding that unexpected problems can crop up with virtually any building material.
D.R. Johnson referred questions to its outside public relations representative, but the call was not returned.
Clark said that 574 CLT panels had been set at the time of the incident, and that only 60 of them remain to be installed. The inquiry by an outside engineering firm was to extend into next week.
It’s a rare sour note for a building material that is seeing wider use on commercial projects in the U.S. and Canada. Proponents say CLTs have a smaller carbon footprint than more conventional steel-and-concrete structures, and can shorten construction times. Panels have been used successfully on a number of well-publicized projects around the country, including a building at the University of Massachusetts (see the “Related Articles” sidebar above) and an office tower in Minneapolis. A number of other buildings made with CLTs are in the works.
Clark says the university intends to complete Peavy Hall with the panels, as soon as engineers have taken a look at the one that failed and certified that others on the project are sound. The building is due to be completed early in 2019.