WholeTrees Lifts Roundwood to New Heights: Commercial Installation Complete in Madison

WholeTrees LLC, a long-time partner of the Forest Products Laboratory (FPL), has completed the installation of structural columns and trusses made from- you guessed it- whole trees, in a Festival Foods grocery store currently under construction in Madison, Wisconsin.

New grocery store features WholeTrees technology. Photo credit: Heartland Images Photography

The new grocery store features WholeTrees technology. Photo credit: Heartland Images Photography

For the project, which broke ground last fall, WholeTrees worked closely with Tri-North, Gebhardt Development, and the City of Madison to re-purpose ash trees for use as structural columns in the store. The trees had previously been removed due to emerald ash borer disease .

WholeTrees also provided 88 structural trusses made with local red pine. The WholeTrees Wing Truss spans 30′ to 60′ with design loads of over 350 pounds per linear foot, and over 10 pounds of carbon stored per square foot.

Similar trusses were recently tested at FPL as the latest in a collaborative effort to demonstrate the technical feasibility of using tree stems in their original form as structural building components.

WholeTrees’ website features a great slideshow following the trees from harvest to installation that’s worth a look.

For more information on the project, see this feature story from Isthmus on WholeTrees’ involvement in the Festival Foods development.

Creep Performance of Structural Insulated Panels (SIPs)

Few places in the United States can understand cold like the Midwestern United States. In Wisconsin, where January’s low temperatures average around 13 degrees Fahrenheit and snowfall is typically measured in feet, a well insulated home can spell the difference between enjoying the winter and enduring the winter. At the Forest Products Laboratory (FPL) in Madison, Wisconsin, helping to evaluate effective yet structurally sound insulation methods for wooden construction is a small but important part of the laboratory’s vast repertoire.

Modern construction efforts have incorporated more and more structural insulated panels (SIPs) into designs—and with good reason. SIPs are a panel-shaped building material that consist of two wood-based composite boards with an insulating layer of foam plastic in between them. The end result is extremely strong, energy efficient and cost effective.

Creep test setup for a structural insulated panel.

Creep test setup for a structural insulated panel.

Although SIPS have been used in floor and roof applications for years, little is known about their long-term structural integrity. Recognizing this gap, researchers at FPL set to work investigating the “creep performance” of these systems, or the tendency of the panel to deform when subjected to a sustained load. The rate of creep deformation is a function of material, time, temperature, moisture, and applied load—and the right combination could spell structural failure.

The project, in cooperation with The Engineered Wood Association (APA) and the Structural Insulated Panel Association (SIPA), began in 2013 when 12-inch-wide panels were brought to FPL to be subjected to 90 days of shear and bending tests. The SIPs performed very well, and all of the 24-foot-long sections survived without any bending failure. In addition, after a recovery period, researchers retested the panels to determine the residual strength of each panel. Again, the SIPs remained strong, unfazed by the 90-day test.

Based off the positive results from the first test, the team launched into the next phase of the project. The second phase kicked off in 2014, and was much more comprehensive than 2013’s efforts. This round of tests involved as many as 28 specimens per test configuration, several different configurations, and lasted into spring of this year. Although the research is completed, the final report has yet to be released—but when it is, building professionals will have a new body of knowledge that will allow them to incorporate SIPS into designs with added peace of mind.

When the days get darker and the snow begins to pile up, SIPS have always been trusted to keep the cold air out. Now, consumers will be able to rest assured that bending, shearing and other deformation won’t be creeping in at night either.

Solid Research on Shaky Science: Building with Wood in Earthquake-Prone Regions

Nepal 2015—Japan 2011—Chile 2010.

In the past decade, these nations, and many others, have been host to some of the most destructive earthquakes in recent memory. Along with the inestimable human and emotional toll these events take on communities around the globe, the costs associated with reconstruction efforts are equally astronomical, often edging into the billions of dollars. Although we can’t effectively predict or stop earthquakes from occurring, we can be ready, and minimize the impacts of these damaging seismic events.

CLT concept and use in a nine-story mid-rise building in London.

CLT concept and use in a nine-story mid-rise building in London.

From relatively stable ground in Madison, Wisconsin, researchers at the Forest Products Laboratory (FPL) are searching for better ways to build more resilient, taller, safer, and cost effective wooden structures for use in earthquake-prone areas of the nation. For the wood building community, the most viable tall building construction solution incorporates the use of cross-laminated timber (CLT).

A CLT panel consists of multiple layers of kiln-dried lumber boards stacked in alternating directions, and bonded together with structural adhesives. The end result is an inexpensive, strong, solid, rectangular panel that can be used for building walls, floors or roofs.

CLT has already established itself as an important building material in Europe, but is relatively new to North America. Wooden buildings over eight stories tall, which incorporate CLT into their design, have sprung up in areas of low seismic activity to include Sweden, Australia, and the United Kingdom. Experts believe that CLT could also be a cost-effective and environmentally friendly alternative to traditional construction materials for buildings up to 125 feet tall.

FPL, along with the Coalition for Advanced Wood Structures, is developing seismic design perimeters for CLT use that will meet or exceed both design and safety codes. The team hopes that the project will lead to the development of a performance-based seismic design (PBSD) methodology to investigate the feasibility of three prototype systems. This PBSD would allow for the construction of buildings in earthquake-prone areas up to 14 stories tall using CLT components.

Researchers believe that this project will lay the ground work for buildings with elongated natural periods, near elastic behavior, and an increased resiliency to the high forces and accelerations of seismic events.

The growing trend of urbanization has increased the need for taller buildings across the country, including in areas that are crisscrossed by tectonic boundaries like California’s San Andreas Fault or the Cascadia Subduction Zone of the Pacific Northwest. At the same time, more emphasis has been placed on environmentally and fiscally responsible construction. Properly rated CLT construction holds great potential for cities like Los Angeles or Seatte—urban areas that have already witnessed tragedy in the past, but hopefully, when and if the next disaster occurs, can be headline-making cities for their successful implementation of safer building techniques.

For more information on, see this Research In Progress report.


FPL Welcomes Deputy Chief Weldon as Leaders Converge in Madison

Last week, The “Destination of Innovation” had a welcomed visit from Leslie Weldon, Forest Service Deputy Chief for the National Forest System.

FPL engineer Robert Ross briefs Deputy Chief Weldon on the air cannon test.

FPL engineer Robert Ross briefs Deputy Chief Weldon on the air cannon test.

Deputy Chief Weldon spent part of the week participating in a Forest Service joint leadership team meeting comprised of representatives from the Forest Products Laboratory (FPL), the Northern Research Station, Region 9, and the Northeastern Area. The Forest Service’s Middle Leader Program was also on site for the week and was fortunate to have Weldon meet with their group. Her perspective as a member of the Forest Service Leadership Team and her willingness to share her experiences went a long way to making the big week a tremendous success.

“By almost all standards, I believe this was one of the most successful leadership meetings I have attended,” said Michael T. Rains, Director of the Forest Products Laboratory and Northern Research Station. “The voice of “one Forest Service” is beginning to get quite loud and it sure sounds good to me.”

Weldon and the Middle Leader participants were able to break away from their meetings and see FPL research first-hand. The group was lucky enough to see one of FPL’s most impressive tests … a shot from our air cannon. It’s not every day one sees a 2×4 piece of lumber flying at 100 mph toward a test wall!

This was the third straight year FPL played host to the leaders from the three mission areas, as well as the up-and-comers in the highly successful middle leader program.

Check out these blog posts for more on FPL’s air cannon and safe room research.

Shelter from the Storm: Discovery Channel Features Safe Room Research

Discovery Channel Canada recently spent a day at the Forest Products Laboratory (FPL) to film a segment on Bob Falk’s tornado safe room research. Falk, a research general engineer at FPL, is developing plans for a do-it-yourself tornado safe room made from commodity lumber. His research, which involves shooting 2×4 lumber from an air cannon at 100 mph, was featured on the show Daily Planet and the results are a blast.

See for yourself at http://www.discovery.ca/Video?vid=592208

FPL engineer Bob Falk talks tornado safe rooms with the Discovery Channel. (Click photo for video clip.)

FPL engineer Bob Falk talks tornado safe rooms with the Discovery Channel. (Click photo for video clip.)


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