For centuries, wood was civilization’s primary construction material, but as the use of concrete, glass and steel grew, wood was largely relegated to flooring and interior paneling.
An exhibition at the National Building Museum in Washington challenges that narrow use. It suggests that tomorrow’s buildings will or should be constructed of wood.
FILE - An upper floor of Lever Architecture headquarters, a four-story all-wood building built using cross-laminated timber stands in Portland, Ore., Nov. 15, 2016.
The exhibition, “Timber City,” highlights the wide range of benefits offered by cutting-edge methods of timber construction, showing that wood is a modern, strong and versatile material.
Winners of Tall Wood Building Prize
The show highlights the two winners of the Tall Wood Building Prize, sponsored by the U.S. Department of Agriculture.
“One in New York City and one in Portland, Oregon, are two premier cross-laminated (engineered, pre-fabricated) timber buildings going up right now,” said the exhibition’s curator, Susan Piedmont-Palladino. “They’re similar structures. Both buildings are using this material ... in slightly different ways, but the goal is to build right in the middle of the city.”
And that’s what makes timber the perfect choice in a busy district like New York’s Manhattan, where construction speed and efficiency are vital.
“Buildings go up very quickly. The materials for the building — the walls and the floors and the ceilings — are manufactured off-site. They come on a truck, pre-fabricated,” Piedmont-Palladino said. “So a work crew armed with power screwdrivers can basically assemble the building extremely quickly. There’s no long-term curing of concrete” needed.
Information panels in the exhibition explain that concrete manufacturing is the world’s third-largest source of greenhouse gases, and that harvesting timber — a renewable resource — has a lower environmental cost than mining the materials needed to make steel and concrete.
FILE - A piece of cross-laminated timber in Portland, Ore., Nov. 15, 2016. CLT is made up of 2-by-4 beams laid out in perpendicular layers that are then glued together to make giant panels.
New manufacturing techniques make cross-laminated timber stronger. Piedmont-Palladino compares it to giant sheets of plywood, placing her hands at 90 degrees on top of each other to demonstrate how it’s made.
“So it is layered, one layer this way, another layer that way, another layer that way, and that way,” she said. “It’s what we called dimensionally stable. It doesn’t move around. And it can be manufactured from small trees that otherwise have very little economic value.”
The curator also says layered timber resists fire better than unprotected steel, which weakens faster than wood when heated. A recently constructed fire station in Oregon, covered with blackened wood from a local flame-damaged barn, demonstrates how a charred exterior actually protects wood from fire.
In addition, Piedmont-Palladino pointed to a psychological benefit of wood construction.
“There’s this concept of biophilia, that is the theory that we are attracted to and relaxed by, and in general our mental and physical health is improved by, being in proximate condition to nature or the elements from nature,” she said.
Timber may not be the best building material in every situation, but the National Building Museum predicts that soon there will be a lot more wooden buildings around the world.
The National Building Museum’s “Timber City” exhibition runs through September 10, 2017.