Ever since the 10-story Home Insurance Building in Chicago was called the first “skyscraper” in 1885, architects have been striving to create ever-taller buildings. Ten stories quickly became 20, 20 became 50, and on and on. In 2009 the Burj Khalifa in Dubai became the world’s tallest building, with its 154 floors towering above ground level.
So why is the mayor of Portland, Oregon, calling a modest 12-story tower set for completion there next year “a true technological and entrepreneurial achievement?” It’s not the affordable housing the building affords, nor its dozens of bike racks or even the roof farm that has Ted Wheeler gushing. It’s that the Framework apartment building will be made almost entirely of wood.
Once completed, Framework will be America’s tallest wooden building and its first “plyscraper” — a high-rise building built with panels made of cross-laminated timber (CLT). These modular sheets are made from cheap, sustainable softwood that are glued or pinned together in layers — a bit like super-strong, super-thick plywood.
While the raw material might vary in quality, CLT (also known as mass timber) is engineered to be stronger than concrete. CLT panels resist earthquakes and even fire, charring instead of catching alight like the lumber in typical homes.
Plyscrapers can be bolted together in days, and they require a fraction of the labor use to erect traditional steel-and-concrete high-rises. “You don’t need an experienced master carpenter to do this,” says Casey Malmquist, founder of Columbia Falls, Montana-based SmartLam, one of only two CLT manufacturers in the U.S. “It literally goes together like Legos.”
From NBC News: https://www.nbcnews.com/mach/tech/eco-friendly-plyscrapers-are-rise-here-s-why-ncna793346