Time was, wood construction had serious limitations where commercial, tall buildings were concerned. But with new materials and a refocusing on code requirements for tall wood buildings, the times might be changing.
The International Code Council (ICC) plans to announce new findings in its exploration of “Tall Wood” construction this fall. Its Tall Wood ad hoc committee was created to learn more about the possibilities that new wood materials might offer, says Architect Magazine. This means the wood construction limitations of the past might finally be overcome, at least to some degree.
Current Code Prohibits Tall Wood Construction
Typically, wood construction isn’t possible in America for buildings taller than 6 stories. Architect Magazine says that the existing fire codes throughout most cities limit construction to four, and sometimes 6 stories at the most. And in some locations, the risk of fire is viewed as so great, tall wood construction is prohibited across the board.
But proponents of wood construction of larger buildings say the code is outdated. For example, firefighting materials and methods have improved greatly over what they were when the code was laid out. Not only that, fire-resistant building materials have shown great improvement. With advances in practices and materials fabrication and use, many believe that the evaluation of tall wood construction is long overdue.
New Materials Could Make Taller Buildings Possible
When fire and building code in many cities was established, some of the building materials that are gaining ground now didn’t exist at all. At that time, a tall wood structure meant more traditional materials. But they aren’t strong enough or fire-resistant enough to perform as safely as other materials, such as the more common steel. Then Cross-Laminated Timber (CLT) and Laminated Strand Lumber (LSL) threw their hats in the ring.
CLT is known as extraordinarily strong. Fire Engineering says that it’s nearly as strong as concrete. But it’s also fire resistant, which changes everything that’s known about wood construction. As for LSL, The Woodworks company says they’re strong, straight, appropriate for tall wood construction, and they can be a component of “1-hour fire rated wall assemblies.” With both materials, more testing is needed to determine their actual performance.
New York and Oregon Lead the Way in Tall Wood Demonstration
Although tall wood construction is prohibited throughout much of America, the U.S Department of Agriculture has recognized the importance of further investigation and experimentation. Their U.S. Tall Wood Building Competition selected two demonstration projects for funding, one in New York and another in Portland, Oregon.
“Next-generation lumber and mass timber products are becoming the latest innovation in building,” says the U.S.D.A. They’re “flexible, strong, and fire resistant, and can be used as a safe and sustainable alternative to concrete, masonry, and steel. Using wood helps to reduce greenhouse gas emissions by storing carbon and simultaneously offsetting emissions from conventional building materials.”
Tall Wood construction might get a sideways glance in some parts of the country, but architects, code officials, fire engineers and the U.S.D.A. recognize that it might be a viable approach for the future. The primary obstacle is overcoming set-in-stone code regulations. But this fall, the ICC might have even more information to further support this shift in the way that we design tall buildings.
Architects are innovators, and tall wood construction could be an innovation that changes the course of history. You can do your part to stay on the cutting edge of developments by keeping professional development hours current. That’s why PDH Academy exists. Check out our courses for architects and learn how hassle-free education can be.