SEELEY LAKE – To look at the new home on Spruce Drive in Seeley Lake, no one would think it was built from the inside out. Seeley Lake resident and general contractor Chris Chitty built his home using engineered wood products including cross-laminated timber (CLT) panels and wood fiber insulation from the Czech Republic.
While the mass timber panel industry is a new phenomenon in the United States, within the past five years it has started gaining popularity in constructing multi-story buildings entirely out of wood that go up very quickly.
Chitty is one of the first in the area to utilize the new technology and build an entire residential home. While he is excited about the potential of someday being able to purchase the products in the United States, until they become readily available, he feels it will be slow to take off in the residential sector.
As reported in the 2021 International Mass Timber Report, CLT is the most widely known mass timber panel product. CLT has been in Europe for 15 years and in the US for 10 years. In the last five years it has really gained popularity.
CLT is comprised of cross-layered pieces of dimension lumber (2X4, 2X6 or 2X8 inch) or structural composite lumber bound together by structural adhesives, nails or hardwood dowels. This creates a solid piece of wood that can be up to a foot thick. Depending on how the lumber is bonded determines the load-bearing capacity and uses such as walls, floors or roofing material.
The Mass Timber Report identified structural CLT panels as specialty products. The panels are custom produced, fabricated and engineered off-site to address specific project requirements. All windows and doors are precut into the walls.
Because the panels are heavier, they require equipment to move them and trucks to haul them. Once they arrive at the building site, they are set with a crane, secured to the foundation and bolted together. Multi-story buildings can be built entirely out of wood and be constructed in a matter of days.
CLT is also gaining popularity because wood is a renewable resource, unlike concrete and steel, and the structures are storing more carbon that in a normal stick frame building. The panels are incredibly resistant to fire and earthquakes. Finally, CLT allows for the ability to have wood walls which many people find aesthetically pleasing.
SmartLam, in Columbia Falls, Montana, was the first manufacturer of CLT in the United States. F.H. Stoltze Land and Lumber Company, also located near Columbia Falls, Montana, announced in August 2020 that it is teaming with a group of partners to form Stoltze Timber Systems, Inc. They plan to build a CLT facility where they will target the use of small diameter trees that are less than 10 inches in diameter breast height. Instead of using the trees for pulp, they make CLT out of 2X2 inch material suitable for homebuilding and other construction products. This would make the small diameter timber economically worth harvesting.
"You can take all this pre-commercial thinning, all this small diameter timber that doesn't have any value right now except for hog fuel, and give it a market," Chitty said. "To have a really good use for that is going to be super helpful for the whole timber industry."
Chitty has been in the construction trade for 20 years. He is currently a general contractor in the firm Hone Architects and Builders out of Missoula. He was intrigued with CLT and wanted to gain the experience working with it so he could offer it to his customers.
"I'm able to take risks with my house that I wouldn't be willing to take with my clients'," Chitty said.
While designing his home on Spruce Drive, he worked with Pat Clark, principal in Wooden Haus Supply in Whitefish, Mont. and partner in Stoltze Timber Systems, Inc. Clark brought considerable experience in European mass timber production and construction.
Chitty imported most of the material for his home from the Czech Republic. All the walls are solid wood engineered panels that are 2 and 3/8 inch thick faced with spruce veneers. CLT that is manufactured in the U.S. has a minimum thickness of 4.25 inches.
"That is way overkill for any residential project," Chitty said. "That is why we had to import that stuff which, believe it or not, is cheaper even with the containers."
Chitty said the vision of simple assembly with the panels is dependent on getting a semi-truck to the job site, having a crane on the job site and having an acre to unload everything and pick through the stacks of material that are optimized to fit on a trailer but not arranged in the order needed for construction.
"We didn't have that luxury," Chitty said.
Chitty used the Cahoon family's log yard on Highway 83 to trans-load. The five- and six-meter panels were thin enough to cut with a skill saw, so he cut them off the stack as they came because he didn't have the room to scatter them out and bring in a semi-trailer.
He and his younger brother cut and set the four gables with a crane in a day in June. Then they started stacking the long walls piece by piece as they went.
Since he used spruce, a soft wood, it was a challenge to keep it nice since it was the interior, finished wall. It also yellows in the sun. Once it was installed, they finished it with an oil wax with UV blockers to keep it blonde.
The roof panels were next to ensure the finished surfaces did not get water damaged.
Chitty continued to build the house to the outside. He added engineered spruce studs to the outside. He purchased these from the Czech Republic as well since they are not offered in the US. He blocked the windows and mounted them from the outside. Then he added the insulation.
Chitty said he tries to stay away from foam insulation. Not only is it a petroleum product and when it burns it releases toxic gases, it is also vapor closed and doesn't allow moisture to escape. Instead he used wood fiber insulation in the ceiling and a high-density wood fiber rigid insulation board on the walls. It is not readily available in the US except as a low density. It is tongue and groove so it fits together and it is coated with wax, making it watertight.
"When you are making cross-laminated timber and you are making all these engineered wood products, you have all this chip left over. You can take that and make insulation out of it," Chitty said. "It is really great because it is nice and rigid. It solves a lot of problems. It is a really cool product."
The structure is "super airtight" because all the joints are air sealed. In addition to the wood fiber, fiberglass insulation is blown in the wall cavities.
"For it being airtight, thick and a lot of R value, this is going to have an R value of 25 in the walls and 50 in the ceiling," Chitty said. "This is going to be probably twice as good as a code minimum house in the end with the air tightness."
Chitty had his new home dried in within three weeks. He estimates it would have taken him four weeks to get a stick frame home to the same place.
Chitty has done a lot of work with structural insulated panels and panelized stud walls. He said even though he was working with different products, having the prior experience working with panels was valuable and helped this progress smoother.
When comparing cost to a stick frame home, Chitty said it is definitely more but it is hard to make a direct comparison. While the panels cost more, sheet rock is not needed. While there are finishing costs and the cost of the crane, he saved time on labor. Due to the labor shortage, having more of the labor done off-site, allows the carpenters to be more productive.
"This will never replace studs and plywood, there just is no more efficient way to build a house," Chitty said. "You might frame floors out of it, you might frame roofs out of it or there are certain elements you might use it for. We just don't really know yet because we don't have access to it to explore all the possibilities."
Chitty recognizes the custom work is never cheap or easy. However, he would love to offer a cabin product at an affordable price that makes sense to use in the area.
"I'm hoping as some of these products become more available, it will become more applicable to the folks in this area," Chitty said. "I think in the end you are going to find it is really useful for floors and big vaulted ceilings [to be installed] really fast but the walls are still going to be stud walls... The panels are really overkill. However, to have more overlapping products that you can choose from is helpful."
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