The simplest answer is often the right one. You may not remember the name of that logical principle (Occam’s razor) but current trends in the construction industry are confirming its truth. Considering all the technology at our fingertips, it’s easy to imagine the next great construction material as complex and other-worldly. Yet one of the world’s simplest construction ingredients, wood, is looking like the leading building material of the future.
Cross Laminated Timber (CLT) is the innovative product that has thrust wood back into the construction spotlight. Some are even suggesting that wood will take the place of concrete and steel framing in the future. Think of plywood, with the fibers running every direction, thereby increasing strength. Well, CLT works similarly. Some engineers jokingly refer to CLT as “plywood on steroids.” Full-size timber is situated at right angles, adding impressive strength.
At a handful of CLT factories around the globe (5 in Italy, 2 in Canada, and 1 in the US), enormous finger jointers gather and press wood scraps to create long pieces of timber. Next, a robot arranges the pieces, and tons of pressure is applied. To finish off residential CLT, a router may be used to carve out window openings as well as spaces for plumbing and wiring. When used in large building projects, CLT panels may be up to six inches thick! By using CLT panels throughout a building, the world’s architects are reaching new heights for timber-only buildings.
Benefits of using CLT for Large Construction Projects
- Wood is a renewable resource. Certainly, steel and concrete may be recycled. Indeed, as Pacific Northwest demolition asset recovery experts, we are one of the largest recyclers of these materials on the West Coast. However, steel and concrete are not as renewable as trees; we can’t grow new mines, but we can grow new trees.
- Wood buildings act as carbon storage devices. At nine stories, the Stadthaus by Waugh Thistleton is one of the world’s largest residential buildings with timber framing. Its designers claim that the Stadthaus stores 186 tons of carbon sequestered within its wooden walls. Overall, the Stadthaus designers claim to have saved 323 tons of C02, both through sequestration and through reduced C02 to obtain wood and construct the structure.
- Wood does not require as much energy to produce as is needed to produce steel and concrete. It takes less carbon to grow and harvest trees than it does to mine materials for concrete and steel.
- The extreme density of CLT panels makes them fire-resistant. This is counter-intuitive, given the history of sweeping fires across the timber-framed cities of the twentieth century. However, CLT is so dense that it chars on the outside while protecting the interior. Actually, CLT outperforms steel in this way, as steel will melt or become brittle under fire.
- CLT panels are prefabricated, and therefore extremely easy to assemble. CLT construction requires about 30% less time than steel-and-concrete framing.
- CLT paneling is ideal for the modern approach to building design, in which architects use 3-D AutoCAD software to create material specs. CLT paneling can be cut to design while still in the factory.
As demolition and asset recovery contractors, we can’t help but speculate about the end-life of CLT panels. Given that they are constructed of wood scraps, it seems possible to recycle CLT panels time and time again—an additional advantage.
Eco-conscious readers may be wondering about deforestation stemming from CLT construction. Certainly, if the world transitions to wood as the primary construction material, we will require plenty of trees. However, there’s reason to be optimistic. First, CLT panels could make good use of millions of dead trees across North America. The Pine Beetle has decimated forests in Canada and the US, leaving wood standing, just waiting to catch fire and release stored carbon into the atmosphere. Wouldn’t it be better to harvest that dead wood, and use it in CLT panels? As with all engineered wood, CLT panel construction allows the use of knotty and otherwise imperfect lumber, such as BKP (Beetle Kill Pine.)
If contractors and designers opt for eco-friendly timber, such as FSC-certified wood, CLT panels could be sustainably produced. Cities of the future could be huge carbon sinks, with C02 sealed away in wood high-rises. As your leading demolition and asset recovery contractors, you can bet we’ll be following the development of CLT as we learn how to safely demolish and reuse this fascinating new building material.
[photo by: Deena Jones on Flickr via CC License]