Timber Towers Using CLT Grow Markets for Wood
Continued advances in cross laminated timber (CLT) and wood framing techniques now make wood high-rises practical. A key enabling technology are adhesives.
Architects Skidmore Owings & Merrill provided an update on urban construction trends at last month's American Assn. for the Advancement of Science in Chicago. Attendees we spoke to were excited to learn of SOM's re-engineering and re-design of plans for its existing 400-foot tall, 42-story concrete apartment building - built in 1965 - re-imagined using wood as the principle construction material. The verdict: wood high-rises are strong enough to be tall. And surprisingly, wood structures are also fire-resistant enough to be practical.
The business case: wood high rises are economically and environmentally better than steel and glass for housing millions of newly affluent workers in the developing economies, including hundreds of millions of Chinese and Indian urban dwellers. This would create large new markets for North American wood products.
Among organizations advancing the role of wood in high-rise construction are WoodWorks.org and the Softwood Lumber Board, the latter based in Chicago, where it has been funding research into engineering high-rise construction. WoodWorks.org, an initiative of wood industry associations and lumber companies, notes:
“The type of adhesive used at both North American manufacturing plants currently producing CLT is a formaldehyde-free structural adhesive with great moisture performance. Adhesives must be qualified in accordance with ANSI/APA PRG 320 for bonding strength, moisture durability, elevated temperature performance, and heat durability.”
This is definitely a trend to follow.