Story by NHLA; Editing by Panels & Furniture Asia
In an effort to enhance awareness around using wood as an innovative building material, The United States Forest Service awarded Boston-based architectural firm, IKD, $250,000 to fund the construction of the first hardwood cross laminated timber (CLT) project in the United States.
The Indiana Hardwood CLT Project uses low-grade hardwood to create a high quality CLT product that will then be used in commercial projects. NHLA is honored to have helped IKD with this project and would like to recognize NHLA board member Dave Bramlage of Cole Hardwoods for helping to secure the necessary materials for this project.
We had the opportunity to speak with Yugon Kim, the lead architect on the project.
NHLA: What is different from this CLT project and other CLT projects that we’ve read about in Europe?
Yugon Kim: We really wanted to utilise Indiana’s timber resource so we proposed the idea of a hardwood cross laminated timber product using 3 common grade lumber. When we looked at the data we found that over 50 per cent of every log goes to low grade materials like pallets and cants. So we proposed upcycling this material into a new hardwood CLT that really isn’t in use here in U.S.
In Europe, they use a single source material, such as tulipwood. Our project is trying to use mixed species simply so that we have a greater pool of timber species to draw from so that is just a larger resource. We’re basically trying to extract as much fibre into the product as possible and to do this our proposal was to use a wider variety of species that have similar structural and mechanical properties and utilise that in a mixed-species assembly.
NHLA: Which species are you using?
Yugon Kim: We are using oak, hickory, maple, ash and beech because they have a similar elastic modulus so that we can engineer a panel that can deal with those different types of species but we also have a larger pool of resources to draw from. The panels used in this project are the first ever pressing of a full 40’x10′ mix species hardwood CLT here in the United States.
NHLA: How did you get involved with the project?
Yugon Kim: I’ve been working with timber for a long time so about four years ago I curated and designed an exhibition on timber construction here in Boston and that really was at the cusp of when cross-laminated timber was starting to make headway here in the United States. As mentioned before, Europe already had kind of a leg-up but when we started doing the research for that exhibition we realised we were on the cusp of a material revolution.
So we did this exhibition in Boston and then two years later, the National Building Museum in Washington, DC, learned about our exhibition and asked us to adapt that exhibition in Washington, DC. We were really excited about that because of where the Museum is, we had the ability to influence public policy. They were able to use the exhibition as a foundation to introduce the material to senators and other decision makers.
So when we had this opportunity in Columbus to build something in the parameter of trying to use local resources it just made sense based upon the research we had done from the prior exhibitions.
NHLA: From your research and experience, what do you think the future use of CLT is?
Yugon Kim: I think it can change how we see our cities. When you look historically, you can make the argument that America was colonised partly because of the abundance of wood here on the continent. I think we’re all hard wired to see our cities as concrete, glass and steel but I can imagine the future where you walk down the street in a major city and next to these more traditional steel and concrete buildings, you’ll see timber buildings. You can see on the West Coast that’s starting to happen already.
NHLA: What would you say to the naysayers who claim it can’t be done due to fires and other outside influences?
Yugon Kim: There are a lot of preconceived notions that are hurdles for CLT to overcome. One is combustibility, but cross-laminated timber is incredibly safe in terms of fire. We did a lot of research when we did the exhibition and we spoke to people at the fire department and in the end we learnt that firemen actually feel more comfortable going into a heavy timber building because in a steel building at certain temperature point, the steel will suffer a catastrophic failure. On the other hand, timber chars and acts as a natural fire repellent allowing the inner core to maintain structural integrity. Forests have been growing there’s an abundance of timber that is available. If there is more market interest in timber products people will begin to maintain and manage their forests in a more a focused way.
The Indiana Cross-Laminated Project was on display from August – November last year in Columbus, Indiana.