Future Forward Interview: Can Cross-Laminated Timber Replace Concrete and Steel?
Casey Malmquist is CEO and president of SmartLam Technologies Group, the first commercial manufacturers of cross-laminated timber (CLT) in the United States.
V1: Please provide a brief background of your education and career before SmartLam.
Malmquist: I have a BS from Gustavus Adolphus College in Minnesota, a degree in environmental studies.
V1: Did you have any previous work experience before SmartLam?
Malmquist: I have been a builder and developer in construction for 35 years. I still have my construction-development company.
V1: Can you describe what cross-laminated timber (CLT) is and what SmartLam does?
Malmquist: CLT is part of the family of what’s collectively called “mass timber” that includes glue laminated beam, nail-laminated timber, and cross-laminated timber. I think the easiest description is “plywood on steroids.” We make large plates of solid lumber—no typical size, but our current press is 10 feet by 40 feet, so we can make a plate of lumber 10 by 40 by about 14 inches deep. And it’s made with successive layers of dimensional lumber that are typically laid perpendicular to one another. So a long layer and then a short, a long, short. Each layer has an adhesive applied, and then the layers are hydraulically compressed for a specific amount of time to create a monolithic slab of wood that “pound for pound” is stronger than concrete or steel.
It has some interesting material properties. It appears like a concrete slab, but it actually behaves more like steel because of its ductility. From a design standpoint, it has some desirous physical properties that can lend to creative designs. Ultimately, we’re attempting to replace concrete and steel with wood and doing so at a significant environmental benefit. Wood is a carbon store, so in the net equation we’re not carbon neutral, but close, as opposed to very high carbon emissions in concrete and steel.
Wood arguably is the only renewable building material; it can literally be harvested. And our adhesive is kitchen grade—you can eat it, which again goes to the environmental side and sustainability.
V1: Does CLT work for all building applications equally, or is it better suited for some applications rather than others?
Malmquist: It isn’t necessarily a “plug-in replacement” for stick frame or componentized building systems used in light frame construction. It can work better in certain applications, but it’s probably not the most cost efficient right now in that market. The real and current play is when we compete and replace concrete and steel construction in the low to mid-rise construction. CLT was first introduced into the 2012 code to a limited extent and then a greater extent in 2015 and even greater extent in 2018. We’re shooting for an unlimited extent in the 2021 code. So from a code standpoint, it’s an evolutionary process.
But I think low- to mid-rise buildings right now is probably the most intuitive use, substituting for concrete and steel.
V1: Why would CLT would be the best choice for builders over other materials you mentioned such as concrete and steel?
Malmquist: Weight is one. If you get into soil conditions, you can actually reduce your foundation size because we’re a fraction of the weight of those two materials. Speed of build is another incentive. Unlike concrete, where it’s poured in place and you’re just using a commodity material, CLT is more akin to steel in that we’re selling not just the material but an entire building system. We have the largest CLT machine: 180 feet long and 20-some feet wide, where every one of these panels is custom milled to become part of a building system that is lifted into place onsite. It’s like assembling with legos.
V1: Are there any building limitations to using CLT? Are there any sizes or weights where it gets to the point where you can’t or shouldn’t use it?
Malmquist: Like any material, it’s limited to some degree by span, so you get into certain spans that are excessive. The span ratings are commensurate to concrete and steel. There’s an ongoing discussion about its fire resistance, of which they have done extensive full-scale testing in Europe. Europeans have been using CLT for the last 25 years. There’s a ton of data out there, but it’s European testing, so it hasn’t been readily adopted here in the United States. There’s been some in Canada as well. We’re heavy into the regime of U.S. testing protocols to prove out some of these things.
I have a really compelling photo that I use in presentations where there are two failed steel I-beams draped over a timber beam, where the timber survived the fire, and the steel I-beams deformed and failed. It’s a little bit counter-intuitive, but the easiest way to explain is if you’re going to start a fire, have you ever tried to light a log with a Bic lighter? There’s just so much mass there. The fire event will burn into the wood to a certain extent, lose its oxygen source and self extinguish. That is the hallmark of the mass timber; it’ll self extinguish and still have the residual structural capabilities.
V1: Is there an explanation of why Europe has been doing this for a while and the United States has been further behind?
Malmquist: There’s a handful of things like that, particularly in the building industry. I think construction is arguably one of the most stubborn businesses out there. Things don’t happen real quickly, and it’s just a matter of adoption—the old “we’ve been doing this for 35 years.” People are not quick to change.
The big push, and the one that motivates me, is the environmental side. For the last 30 or 40 years, we’ve been in a federally mandated effort to reduce automobile emissions in the United States. Mandates on manufacturers and emissions goals have successfully reduced auto emissions, which are a major contributor to greenhouse gases and climate change. Autos represent about 30 percent of greenhouse gas emissions in the United States, while the building industry—the construction and maintenance of buildings—represents 40 to 45 percent of greenhouse gas emissions. With a growing awareness of climate change, there has been a big impetus toward looking at a low-carbon alternative, and sustainability is another key word that people are focusing on across every industry.
Wood is the only renewable sustainable building material, so I think those are the things that recently have put CLT into the focus and making it more commercially viable.
V1: Where does CLT wood come from and does it have any impact on the world’s forests?
Malmquist: The beauty of it is that we’re taking small wood and making it into bigger wood. Most of the tree stock we use are 12-inch diameter or less, which is a very sustainably harvestable endeavor. All of the mills we purchase from are qualified either by FSC (Forest Stewardship Council) or SFI (Sustainable Forestry Initiative), which is a little more stringent. It actually regulates and encourages sustainable forestry practices.
Our production capability on the new plant is about 48 billion board feet annually, which is about 12,000 logging trucks. How long does it take to regenerate that amount of wood fiber in the North American forest? The astonishing answer is five hours and 12 minutes. Right now, there’s this huge effort occurring to get back into forest lands and manage them in sustainable ways, rather than let them go to rot with beetle kill and catastrophic fire events. It actually supports, in a favorable way, sustainable forestry and sustainable forest practices.
V1: Can you use beetle-killed timber?
Malmquist: Unfortunately no, most sawmills won’t touch it. This gets very politicized. If they’re able to harvest that stuff immediately, yes, but typically it gets tied up in a lawsuit, and by that time the beetle-killed wood is too dry. They tried to do that to a certain extent and had a number of mill fires because the wood was too dry to run through the mills.
V1: Could you describe some interesting projects and applications that use CLT?
Malmquist: One of my favorite aspects of CLT is the diversity in the product line we produce. For example, we started out making industrial matting because it was a good way to learn how to make CLT. Crane mats or access mats typically were large timbers bolted together that they would throw in the ground to set up a big crane and create a temporary road. We were able to produce the same performance with a much thinner mat that’s cross laminated and eliminated harvesting these beautiful, old-world timbers.
Take that all the way to building a multi-story building. Recently in Vancouver, British Columbia, there is a recently constructed 18-story student-housing building that was made primarily out of cross-laminated timber. We’ve made furniture; we’ve made agricultural buildings. It has such great versatility, and it can be applied in several different marketplaces.
I have three buildings that I built for myself that are CLT, and I favor those because they’re beautiful, very functional and went up very quickly. They’ve got great lifecycle potential.
We recently completed an Amtrak train station in Tacoma, Washington. The whole roof system was made out of CLT. We’ve done things from school rooms to office buildings and a wide array. I don’t know if I could “tip my hat” to a particularly favorite project.
Another interesting thing we’re doing is modular elevator shafts. I think this one is a really good comparison, because it does it in a bite-sized fashion. If you take a typical, four-story elevator shaft that goes in virtually every multi-level, multi-unit building, it’s typically made out of concrete masonry units (CMUs) that take a crew of 12 more than a month to build. You have to scaffold inside and out. You have an inspection point with an inspector every eight feet of lift. You’re subject to weather and freeze conditions. We can build that same shaft in our factory in a day and set it on site in half a day and create the exact same structural system.
To me, that’s a great metaphor for the flexibility of this material, the strength of it. But it also speaks to the fact that it’s a system. It’s modular, so the pieces come out pre-milled, and you crane in 4 panels to make the shaft, place a top on it, and you’re done.
V1: Along those lines, where might there be future untapped projects or applications?
Malmquist: We actually “throw that out there” with our customers and prospective customers, trying to motivate them to think of other uses. We have built bridges, grain storage buildings, modular outhouse and maintenance buildings, schools, offices, you name it. We’ve even looked at applying it for sound walls for freeway systems.
V1: How much research and development goes into your products? What does that consist of? Where do you see putting future R&D into?
Malmquist: We invest about 20 percent of our resources into R&D, and that covers everything from using other engineered wood products, looking at other material components. We’re governed under the American Plywood Association (APA), and there’s a standard we need to produce the architectural grade CLT called PRG320. Right now, it’s fairly limited in its scope. It addresses only certain specific species, so we’ve been working on expanding into other species, including hardwood. We’re trying to develop ways to improve the performance of this product in a natural and sustainable way.
We’ve done a tremendous amount of R&D, which also includes testing. From fire performance to seismic performance to acoustic performance, it’s really understanding how this material works, and what things we can pull out of it.
As far as our future company growth, we’ve got this plant here in Northwest Montana, and our goal is within three years to build a plant in the northeast and then the southeast as the market continues to develop and expand.