by Web Editor | Oct 11, 2017 | News
As a crane lowered a glulam beam and construction workers on either end deftly guided it into connection with two upright wooden columns, a tour group member shook his head and said, “It’s like Lincoln Logs.”
Kind of. Which may in part explain some of the attraction of builders and designers to the potential use of strong, precisely engineered, carbon-storing wood beams, columns, wall panels and floor decking. As Chris Evans, a Swinerton Builders project manager put it, wood is the first building material people use to make the forts, homes and hideouts of childhood.
These days, builders and designers are joining mill owners, university researchers and policy makers in taking a fresh look at advanced wood products, “mass timbers” and what’s come to be called “tall wood” design. Advocates believe it can replace concrete and steel in mid- to even high-rise buildings, and provide an economic jolt to rural Oregon in terms of forest management and mill jobs.
In Hillsboro, Evans and Swinerton Builders are overseeing construction of the largest known U.S. building to date that uses cross-laminated timber, or CLT, for flooring, and glulam posts and beams. The Oregon headquarters of First Tech Credit Union will be five stories high and have 156,000 square feet of office space. Swinerton Builders is the general contractor.
Another tall wood building planned for Portland, called Framework, will be 12 stories high and will have five floors of affordable housing. That project was awarded a $1.5 million federal design competition grant to help with seismic and fire testing and certification.
From Capital Press: https://www.capitalpress.com/Oregon/20171005/nations-largest-mass-timber-building-under-construction-in-oregon
by Web Editor | Feb 10, 2016 | News
Last month we saw cross-laminated timbers installed at the Albina Yard project in Portland. It was the first use of U.S.-produced CLT in a building-wide structural system.
The first level of CLT (4,000 square feet) on Albina Yard went up in fewer than four hours. Last week, the second level was installed by a crew of seven in under two hours. Pretty remarkable, considering the contractor says it would have taken at least twice as many people two days or more to frame the same amount of floor space using traditional methods. Albina Yard is a four-story, 16,000-square-foot creative office project in north Portland. Besides its snazzy design by LEVER Architecture, the project is most notable for being tangible evidence that the U.S. CLT industry is officially off the ground.
There’s been a lot of buzz around CLT and mass timber in general over the past several months in Oregon and around the country — and rightly so. Besides drastically improved speed of construction (and the savings that go with that), mass timber offers significant environmental benefits. This includes tremendous carbon-storing capacity. Half the dry weight of wood is carbon. It got there when the trees were growing and absorbing carbon dioxide from the atmosphere. That carbon remains locked up for as long as the wood remains in use (a nine-story wood structure in China is now 959 years old—nearly a millennium). The new trees planted to replace those that were harvested start the carbon cycle all over again.
According to a quick, back-of-the-napkin calculation, Albina Yard, which is small by commercial construction standards, stores about 80.5 metric tons of carbon. That’s equivalent to offsetting 295 metric tons of CO2 emissions.
A larger Portland mass timber building, Clay Creative (60,000 square feet), stores more than 1 million pounds of carbon. Its total of 457.5 metric tons offsets 1,678 metric tons of CO2 emissions. “An additional 3,574 metric tons of CO2 emissions were avoided by using wood rather than concrete and steel,” says Dr. Jim Bowyer, an expert on the subject at Dovetail Partners, Inc.
From the Oregon Forest Resources Institute: https://oregonforests.org/blog/mass-timber-rising
