Stadthaus, a 9-story story building in London that's one of the first modern examples of mass timber construction.
Stadthaus, a 9-story story building in London that's one of the first modern examples of mass timber construction.

Grande Prairie, Alberta

Robert Fouquet was raised in a stone farmhouse on France's border with Spain. Now his focus is half a world away, in a factory in this town 500 miles north of the U.S. border. His goal: make engineered wood as popular with builders as his countryman Gustave Eiffel did with steel more than a century ago.

"We're beginning an era in which wood is going to be viewed in a positive light" by people who have questioned its suitability for certain projects, says Fouquet, vice president for marketing and sales at Ainsworth, the Canadian maker of engineered wood. "You can make oriented strand lumber (OSL) in various grades, like various kinds of steel," he says. "By cutting the wood into strands, then orienting the strands and adding wax and resin, you can create a metal out of wood. The strength-to-weight ratio of the product is phenomenal, and the reliability of its structural properties is sometimes higher than steel."

HIGHER: At Stadthaus N1, an apartment house under construction in London, the frame for the upper eight stories is made of engineered spruce laminates. Most wood construction in America stops at three stories. Employing such wood here could raise that ceiling. Photo: Hammond Lumber, Oregon Historical Society, OrHi 76084 Some builders already get the message. In London, construction is under way on a nine-story apartment house in which the frame for the upper eight stories consists not of concrete or steel, but of Austrian spruce sliced into laminate sheets and then glued in a crisscross pattern. In contrast, most wood-framed buildings in America stop at three floors.

Meanwhile, research labs are expanding the wooden envelope. The University of Maine's Advanced Engineering Wood Composites (AEWC) Center has developed a lightweight wood coating that can withstand up to seven times more energy than conventional wood structures. This could enable the Army to create bombproof MASH units, and civilians to build hurricane-resistant wood shelters.

Researchers are particularly excited about plywood and laminates with layers of fiber-reinforced composites, adding length and strength but not weight to the product.

Others are focusing on glue, "the new four-letter word in lumber," as one Oregon State University professor puts it. Companies are testing resins made from products like soybeans. If they succeed, they'll curb the use of petroleum products in engineered wood. New resins also could reduce formaldehyde off-gassing.

Maine's AEWC also has developed a way to infuse polymer resins into wood more consistently and evenly than is the case now. Called ComPRIS, the technology will save money and labor as well as permit the creation of more complex products, such as products that can be reinforced and laminated at the same time. Imagine skateboards that are lighter and stronger than ever before using low-cost species of woods, or popsicle sticks made of sawdust and thermoplastic, thus having fewer defects than solid wood.

Engineered lumber has been around for decades, but the basic concept remains the same: Slice and dice a log into sheets or strips, reconfigure them, and then glue and iron the result into a useful shape. "We take the defects out of the tree and put it back together again," says Dennis Huston, sales manager for Boise Engineered Wood Products.

Over the past 20 years, engineered wood has sold best when it was turned into panels and I-joists, reaching the point where oriented strand board (OSB) has 82% of its market, and I-joists are nearing 50% market penetration, according to the APA, the Tacoma, Wash.-based association for engineered wood. The next 20 years, Fouquet and other industry insiders say, will see engineered wood used in new locations in a home. Watch for OSL versions of rimboards, headers, beams, structural insulated panels, perhaps even studs.

"Twenty years from now, the same increase in popularity is going to happen with OSL as happened with OSB," Fouquet says. There also will be upgrades to products, such as by using laminated veneers rather than strands on I-joist flanges.

BIG FELLERS: North America's loggers once cut down trees that were so enormous–such as this one, probably located in California–eight men could stand in the notch. Today, the remaining old-growth giants are virtually off limits, and timber companies set up their sawmills for logs that are just six to 20 inches wide. They also employ far smaller crews today, replacing dozens of ax men with a few folks wielding such mechanical helpers as feller/bunchers and delimbers. At the mill, lasers scan the logs so that computers can figure out how best to use, as one company puts it, "every part of the tree but its shadow." Photo: Hammond Lumber, Oregon Historical Society, OrHi 76084 Engineered wood's chief drawback to date has been that it costs more than solid-sawn wood, but its champions believe the gap will narrow as technology and sales improve. Besides, other factors are tilting the board in its favor.

The best solid-sawn lumber comes from huge, old, densely ringed trees, but such trees take the better part of a century to grow. Engineered wood can use younger, thinner trees as skinny as six inches across, as well as combine species and consume a greater percentage of the log. Forest owners can generate more profit by planting and cutting fast-sprouting trees rather than waiting decades for their assets to grow. (See "Owning Up to the Problem," page 40)

Engineered wood also will benefit from green building standards that encourage its use. The APA says that at the conventional spacing of 16 inches on center, floor I-joists use 36% less wood fiber than solid-sawn lumber. And the trend toward open rooms also works in favor of lumber that can span long distances.

Does all this mean the end of the 2x4? "I think that's where mills are headed," says the APA's Tom Williamson, but perhaps not for decades to come. Besides, not all engineering takes place after the tree is cut.

–Craig Webb