State funds pilot projects using innovative materials
Five school districts in Washington are part of a state-funded pilot project using Cross Laminated Timber (CLT), an innovative material that has been used in Europe for decades.
The prefabricated panels are being used to construct four 900-square-foot classrooms within a 4,000-square-foot building at each school. Enclosed walkways will connect the modular spaces to existing buildings.
Upon completion, each building will be used for K-3 classrooms in the Mount Vernon, Seattle, Sequim, Toppenish, and Wapato school districts.
The State Legislature funded the $5.5 million pilot program in 2016. A provision in the state's capital budget that aims to reduce classroom size and stimulate the timber industry is the source of funding for the pilot projects.
The CLT panels have cutouts for doors, windows and utilities and snap together like LEGO pieces, speeding up building times and requiring fewer construction workers. The four-classroom configurations cost about the same as one portable classroom, but education officials say students respond better to a permanent space.
Among structural benefits a project engineer cited is the material's similarity to precast concrete planks or super-thick pieces of plywood. Additionally, the panels don't ignite as easily as conventional wood-frame construction.
State officials say the panels are strong and rigid enough to replace steel and concrete. They also believe the use of CLT could help solve the dilemma of what to do with millions of beetle-kill fir and pine trees that pose huge risks of forest fires. CLT uses small-diameter softwood that can't be used for traditional dimensional lumber and is considered a waste product.
CLT has been used in a few local projects. They include the First Congregational Church in Bellevue, a home in Seattle's Madison Park, and Shoreline Medical & Dental Clinic.
Currently, there are no CLT manufacturers in Washington and only a few in North America. Forterra is leading a statewide coalition to develop a market for the sustainable production and use of CLT. An effort is underway to revive the forest products industry in the Skykomish, Stilliguamish, and Skagit River valleys to develop cross laminated timber using 20-to-30-year old trees.