recent closures of at least four paper mills and two biomass plants.
The current center of CLT talk in Maine is the Advanced Structures and
Composites Center at University of Maine at Orono. The lab pioneered
wood-composite glulam bridges in 2001, then moved on to offshore wind
development. I recently toured the airplane-hangar-sized facility with Russell
Edgar, lab operations and wood-composites manager. He showed me how
CLT panels earn their grades in a vertical viselike machine that delivers a
crushing weight that’s equivalent to that of a locomotive engine. Testing has
found that CLT panels made from Maine-grown red-spruce lumber break
more easily than those made from Quebec-grown black spruce or West
Coast-grown Douglas fir, according to Edgar.
But it turns out that one of the most durable combinations is red-spruce
lumber sandwiched around a core of laminated strand lumber (LSL) made of
pressed aspen chips. The spruce handles the compression and tension forces
on the outside faces, while the LSL panel handles the rolling sheer force inside.
“It kind of made sense; it was the perfect match,” Edgar said. The hybrid panels meet or exceed the standards of the American National Standards Institute,
although the ultimate arbiter will be the marketplace, he said.
“Where does a hybrid CLT fit?” he mused. “Which grade is there market-
The materials testing is one of the many early steps in developing a wider
market and, ultimately, determining whether there is enough demand to
justify a CLT manufacturing plant in Maine.
“We’re behind the curve, for sure,” said Edgar, referring to the three Canadian
CLT mills and one Oregon mill already in operation. But after attending a mass
timber research workshop in Wisconsin last November, Edgar has become
bullish. “There is serious momentum behind this. . . . This is going to happen.
There’s a critical mass of architects and engineers. It seems like it’s inevitable.
The only question is how much time it will take to get a plant built.”
It will be a slow process, predicts Lloyd Irland, an economist and forest
industry consultant. “The amount of ballyhoo per square foot that this is
generating is infinite,” said Irland. “We’ve heard breathless examples of
individual buildings. But we don’t have any idea what the demand will be.
Really, new building concepts don’t happen overnight.”
While beautiful “prestige” wooden buildings like the UMass Design Center
capture imaginations and help to promote awareness of new technologies,
it’s far more numerous commercial structures that will drive the need for a
CLT plant, he said.
“For every architect that’s excited, there’s a half-dozen others saying, ‘my
clients don’t want that.’ A lot of building clients are more interested in func-
tion, service, and cost. They’re not interested in stunning.”
Patrick Strauch, executive director of Maine Forest Products Council, sees
the tall building competition, recent federal legislation accelerating research
and development of CLT, and strong demand for bio-based products as all
pushing a “renaissance in the use of wood, coming full circle.” An example of
that renaissance is a new affordable housing project in downtown Portland,
notes Senator Angus King, I-Maine. Avesta Housing used prefab wood frame
construction – instead off conventional concrete and steel – in constructing a
four-story, 42-unit, multifamily housing project in one of the city’s low-income
neighborhoods. The design won an award for lowering the cost of housing.
“It’s kind of back to the future,” King said.
Above: The new cross-laminated timber Design Center building goes up at UMass Amherst last winter; it’s quite a contrast to the appearance of the concrete building beside it.
Below, left: Russell Edgar, lab operations and wood composites manager at the Advanced Structures & Composite Center, beside a stack of cross-laminated timbers.