Western Red Cedar
Cedar's Historical Significance to Canada's First Nations and Native Americans
While currently trendy, Western Red Cedar is not a new phenomenon. A large number of archeological finds indicates the widespread use of Western Red Cedar in ancient native cultures. It was used extensively wherever it was found along the northwest coast of North America, including British Columbia, Washington state, Oregon, Idaho, and parts of Alaska.
Photo courtesy of the Western Red Cedar Lumber Association
While currently trending in contemporary design, Western Red Cedar has a proven history of use and performance dating back thousands of years.
Bark baskets woven in five different styles have been found near Vancouver, along with ropes and ocean-going canoes dating to 3,000 years ago. Woodworking tools such as carved antlers, dating between 8,000 and 5,000 years ago, were discovered in shell middens at an archeology site near Vancouver. Tools dating 4,000 to 3,000 years old have been found on the west coast of Vancouver Island. Wooden artifacts 1,000 years old were unearthed on the east coast of Vancouver Island.
The cedar trees and their wood have deep religious values. In a book titled Cedar: Tree of Life to the Northwest Coast Indians, author Hilary Stewart mentions a legend among the native Coast Salish people that describes the origins of the Western Red Cedar.2 The legend focuses on a generous man who gave the people whatever they needed. When the Great Spirit saw this, he declared that when the generous man died, a great red cedar tree would grow where he is buried, and that the cedar will be useful to all the people, providing its roots for baskets, bark for clothing, and wood for shelter.
Native Americans of coastal Oregon to southeast Alaska also have a long history of using Western Red Cedar. Some northwest coast tribes refer to themselves as “people of the redcedar,” using the original spelling because of their connection with the tree for their basic needs. Roots and bark were used for baskets, bowls, ropes, clothing, blankets, and rings. The wood has been used for houses, boards, ceremonial objects, totem poles, masks, utensils, boxes, boards, instruments, canoes, and vessels.
Therefore, the specification of Western Red Cedar in contemporary architecture carries with it a deep and meaningful link to the history of native cultures.
Western Red Cedar's Characteristics
The scientific name for Western Red Cedar is Thuja plicata and has one of the widest spread growth ranges on the West Coast. It is often found growing alongside Douglas Fir and Western Hemlock. It grows in lush forests and mountainsides, and also in many forested swamps and stream banks in its range.
Photo courtesy of Houry Avedissian
Western Red Cedar’s scientific name is Thuja plicata. The name is derived from thujaplicin, a chemical substance that is found in mature trees and serves as a natural fungicide, thereby preventing the wood from rotting.
Western Red Cedar is one of North America’s great renewable resources. Slow growing and naturally durable, it has one of the longest life spans of any North American softwood. It produces various lengths of timber with true, straight grain.
Western Red Cedar’s celebrated durability actually reveals itself long before harvest. A report by Connie Harrington of the U.S. Forest Service, an agency of the USDA, stresses that the tree tolerates shade very well. “Cedars have a reputation for surviving in the understory with (slow) growth,” Harrington states. Further, the species’ growth rates are likely to thrive as accelerated climate change occurs. And it is “less susceptible to diseases than many other conifers.” The trees can live for more than 1,000 years.3
CASE STUDY: SANDY HIGH SCHOOL
CEDAR HELPS CAPTURE REQUIRED ‘SANDY STYLE’
Photo courtesy of Josh Partee
Because the buildings needed to last at least 75 years, the architecture firm DOWA-IBI Group Architects decided on a proven, durable wood siding.
The $79-million Sandy High School—which accommodates 1,800 students—opened in the fall of 2012 to replace a nearly 90-year-old structure half its size. The school has been described as a big building in a small town: 310,000 square feet for a community of just 8,000 people, halfway between Portland and the historic Timberline Lodge on Mount Hood, Oregon.
Organized as if it were an ancient Roman town, the school is comprised of two parts: one running a north-south axis (which serves as a corridor linking a gym, an auditorium, and dining commons) and one 600-foot-long east-west axis (which leads to three classroom wings extending out to the south and to a double-height library to the north).
The new Sandy High School needed to exemplify the school district’s commitment to quality education and be a center of pride for all communities within the district. In addition, the city’s zoning code required that all new construction conform to the ‘Sandy Style,’ a local design standard meant to celebrate its position as the Gateway to Mount Hood and characterized by Cascadian architecture (which is English Arts and Crafts combined with Oregon Rustic), which was popular between 1915 and 1940.
The Oregon Trail School District was also adamant that the facility would impact the natural landscape minimally and be a model of environmental sustainability. This meant serious attention to building system performance but also building material performance, such as locally produced materials that would last the minimum 75-year life of the building.
Finally, the design needed to be economical to build and cost effective to maintain. Long-term operational and maintenance costs are often the largest burden that public school districts face once their capital construction bonds are spent. In meeting the design requirements, the design team at DOWA-IBI Group Architects in Portland knew early on that it would need wood that was not only indigenous to the region but that had superior durability and was suitable for diverse applications.
Photo courtesy of Josh Partee
The use of Western Red Cedar helped reinforce the desired modern Cascadian aesthetic.
“The natural characteristics of Western Red Cedar came to the top very quickly,” DOWA-IBI Principal John Weekes says when recalling the review of woods that could satisfy the design needs. The modern Cascadian interpretation pointed to a design concept of heavy-timber frames, pitched rooflines, and uncoated WRC board siding, complementing the rural, rustic ethos of the surrounding farm communities. Cedar was also used as roof decking (in 3- to 4-inch thicknesses) with exposed facing, as 8 by 8 quad posts, and for siding.
A whole-building sustainability plan was developed, ensuring the building included a long list of green building strategies. The goal was to “reduce the school’s carbon footprint” and in the process achieve a LEED Gold certification. In this regard, Sandy High was equipped with passive and active solar panels, green roofs, geothermal piping, and an air-displacement system. The school’s distinctive saw-tooth roof brings sunlight into the gym, and skylights perform the same function in other locations. Where shading was needed, deep overhangs and a combination of vertical and horizontal cedar louvers were installed.
Much attention was placed on selecting materials that would last the minimum 75-year life of the building, patina over time and not tire, and require few resources to maintain. Western Red Cedar met those requirements with its natural resistance to moisture, decay, and insect damage and because it can be installed and left alone yet look great over time.
A key decision in this regard was to treat the cedar with bleaching oil to accelerate the aging process and give the timber the grey, weathered appearance that has become associated with the Cascadian style.
With such a large building, cost issues were magnified by the scale and quantity of material needed. DOWI-IBI staff pointed to the first-time cost effectiveness of cedar siding, the favorable natural weathering for long-term maintenance, and avoiding the high cost and high embodied and recurring energies of paint and coatings (an additional sustainability feature).
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