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Innovative Building Materials : Cross-Laminated Timber

Posted By
Jillian Lambert

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“The pipeline for lumber and other wood products demand remains quite deep in 2021…,” these are the words of Dustin Jalbert, a senior economist specializing in wood prices at Fastmarkets RISI, during an interview with Fortune this past April. Anyone with access to news outlets knows that lumber shortages have directly affected building material supplies;  from the traditional product offerings to the more sustainable timber products like cross-laminated timber or CLT. 

CLT is a concept that was developed in Austria in the 1990s. Europe and Scandinavia embraced the idea at the very start, using CLT in residential construction. And many European companies specializing in prefab and custom designs utilize CLT. In 2010, the US began to show interest in its potential to supplement and/or replace steel and concrete in construction. This increased its popularity, however, the residual effects of the pandemic have since hampered production.

The Scoop

CLT is an engineered wood product typically made from wood such as spruce, larch, douglas fir, and pine.  It consists of solid-sawn 2-by lumber that is Thermo sealed in layers. This aids in reinforcing and creating bi-directional structural resilience and soundness. The process for developing the product begins with selecting the lumber, followed by a kiln drying process, defect removal, and trimming. Afterward, each board is stacked perpendicularly (90-degrees) to the adjacent layer and then sprayed with an adhesive, placed in a hydraulic press, and then cut to precise lengths. The finished product is a custom manufactured panel, designed based upon the specifications of the building for which it was constructed. In the U.S., these panels can be three, five, seven, or even nine layers in commercial construction.

Residential construction isn’t the only area that has seen growth in the utilization of CLT. Multifamily projects like the carbon-neutral apartment complex in Boston designed by architecture studio Generate, in partnership with the developer Placetailor, are popping up across the country. 

What Are the Benefits?

CLT construction has provided builders with flexibility and time-saving benefits, while the end-user enjoys efficiency, innovation, and beauty. For example, architects in Finland and Estonia have designed systems around the product that provide greater insulation and storage space for the home’s mechanical and technical apparatuses. While in B.C., a modern passive, net-zero home was engineered using CLT and was constructed in only five days! The result was a structurally sound, aesthetically pleasing home. The efficient process helps to eliminate waste and increase productivity. 

The company Cascade Built was one of the first residential builders in the United States to use CLT. Their 1,500 sq. ft design was built in Seattle and boasts immense energy efficiency since the panels absorb and reemit moisture and heat, helping to moderate fluctuations. Environmentally, CLT would align with the sustainable category in most instances as it is made from a renewable source (wood). And as long as it is harvested sustainably,  there are no concerns about the use of fossil fuels to produce it.

If you are wondering about the safety of the adhesives used to bond CLT panels, you will be pleased to know that they have to meet the same standards that those used in laminated timber manufacturing uphold, according to NC State University College of Natural Resources. And as each panel is cut according to the building's specifications, there is less waste involved. Not to mention that the panels are assembled and shipped a few at a time, minimizing onsite space concerns and possible disruptions, which saves money in the long run. 

For those of you who are strictly interested in the numbers, consider this: the softwood lumber industry claims that “buildings constructed with mass timber or CLT are about 25% faster to construct than concrete buildings. They also require 90% less construction traffic. In addition, when you use CLT instead of concrete and steel, you are decreasing your carbon footprint--kudos to you and a big “thank you” from Mother Earth. 

What’s Not To Love About CLT?

Though the perks of building with CLT are quite numerous there can be a downside to this method. One of the disadvantages of using CLT is the cost. It’s quick to frame with but is ultimately a bit costly. In one study, a comparison was made of three materials used in constructing a 1,850 sq. ft. home. The outcome was that the CLT structure, though completed 22-days faster, was 21% more expensive to build than its counterparts. So when considering this product, you may want to be prepared to dig a little deeper into your pockets when it’s time to fund your project.

Bear in mind that due to the specificity required for a CLT building system, there could be limitations when considering a future remodel. Another point to note is that there is less room for error when working with CLT. Dimensions must fit the plan to a “T” because of the fixed panel sizes. And in turn, those panels must join smoothly without a hitch, otherwise, there may be structural issues.  Where plumbing and electricals are concerned, a strategy needs to be in place to execute proper placement as there are no wall cavities. While there is some wiggle room for slight modifications when in the field, those modifications can considerably impact your budget for the build--so plan accordingly. 

The Bottom Line

During his interview with Forbes, Jalbert goes on to say, “builders have plenty of ongoing projects to keep working through, which is keeping lumber and panel demand high, and making it very difficult for mills to ramp production up fast enough to rebalance the market...” That's not exactly what anyone's wanting to hear right now...but something I learned from a recent summit hosted by Mark Mitchell of Whizard Strategy, is that "pain is a catalyst for innovation and adoption..."

That's quite true--look around, minds are being stretched, new ideas are being birthed, inspiration to problem-solve is in high gear. Not to mention the speculation that both the price of lumber and its availability will even out by year’s end, as the industry continues to ramp up and rebound. The optimist in me wants to agree. Let’s keep our fingers crossed and with bated breath, anticipate the increase of supply and a return to discovering the full capabilities of CLT and other great materials in framing the world around us more thoughtfully.