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New ideas for wood: Replacing road salt, making a building (yes, that’s new)

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Monitor staff
Monday, January 29, 2018

Considering that New Hampshire is smack dab in the middle of a region sometimes called the Saudi Arabia of biomass – i.e., we have lots of trees to sell – it’s a little weird that our logging and milling industries are struggling.

The problem is that many of the industries that used to buy lumber and chipped wood are in decline. As a result, people are trying to find new uses for the trees we cut down and chop up.

This column will look at two possibilities. One – replacing road salt – is kind of goofy but the other – replacing structural steel and concrete in mid-rise buildings – is drawing a serious attention.

Idea one: Replace road salt.

The idea is simple: Grind trees into small chips and sprinkle them over icy roads to speed up melting, adding a dash of magnesium chloride to help the chips stick.

Using chips instead of sodium chloride has big environmental benefits. Wood chips won’t pollute waterways like road salt does and will eventually rot away.

Loggers love this idea because they currently sell wood chips, made from the non-lumber parts of trees like tops and limbs, to paper mills and wood-burning power plants. Both those customers are fading away, one undercut by electronics and the other by cheaper natural gas-burning power plants, which leaves us without any good market for this low-grade wood. That loss has driven some loggers out of business or forced them to abandon best practices in order to break even on jobs.

The idea of chips replacing road salt got a lot of attention recently after Canadian broadcasters picked up the story of a Quebec town that has switched for its icier roads, but the principle has been discussed for a while. Poke around online and you’ll find lots of research about other biological alternatives to road salt, including cheese brine, beets and grass.

These are all promising, but road salt is so cheap and effective that it’s hard for these alternatives to compete unless they get paid for their environmental benefit.

Idea two: Mass timber

Mass timber?

“That’s short for ‘massive,’ not Massachusetts,” said Nicole St. Clair Knobloch, who leads a project called Build It With Wood for the New England Forestry Foundation.

It could be Massachusetts, however, because that state is way ahead of New Hampshire when it comes to looking at new ways to create buildings out of wood using what is also referred to as engineered timber.

Instead of cutting whole trees into lumber, makers of products like cross-laminated timber and glulam (as in glued laminated timber) take many pieces of wood, cut them into special shapes and glue them together to create new shapes.

If done properly, this creates beams and planks that are stronger than plain wood and, adherents argue, can beat even steel in strength, cost and speed of construction – to the point that it can be used to create buildings that are too tall for traditional wood-frame construction.

Case in point: The University of British Columbia (another “Saudi Arabia of biomass” region) built an 18-story dorm using mass timber. If done in New Hampshire, it would be the third-tallest building in the state.

Cool! That’s why I called Knobloch to pick her brains.

NEFF, as it turns out, issued a report last April about the viability of mass timber market in New England, prodded by interest from Massachusetts state government that led to the construction of the four-story, 87,000-square foot Design Building at UMass Amherst, made from cross-laminated timber from Canada. It is called the largest modern wood building in the Northeastern U.S.

NEFF estimates that if just a one or two percent of the region’s buildings that typically use steel were to use mass timber, it could support a couple of major mills in New England alone.

“The biggest advantage comes in mid-rise building,” said Knobloch. “Wood timber frame is cheaper than steel up to about 5 or 6 stories – you can’t go past that fire-wise or structurally – but concrete and steel is expensive at that point. It’s not until about 12 stories that steel costs out” to be cheaper.

The result, she said, is that mid-rise buildings often use what is known as a light steel frame, “which is not the best thermally, not the most airtight.” Using mass timber, she argued, would allow for builders that are more environmentally friendly, not even counting the way the use of timber sequesters the carbon in the wood.

Mass timber can also be cheaper than steel for mid-rise buildings, she said, which leads hope for more affordable multi-unit housing.

However, the product faces a chicken-and-egg situation in the U.S., where we have few mills making it and little experience using it.

“There are a lot of people who want to do it – architects, developers, construction companies, clients like the city of Boston, affordable housing developers – but they don’t know how to price out a product. Cross-laminated timber is not a commodity, you can’t just go down to Home Depot and get what you need,” she said.

Another barrier is building codes. The International Building Code allows wood-frame buildings up to five stories high but any higher and variances are needed.

“A variance is really about fire, convincing the fire marshal that it works,” Knobloch.

Advocates of mass timber say because of the way it is constructed, the product chars rather than burns, making it much safer than wood-frame buildings and on par with steel and concrete. But that’s not obvious.

Knobloch said that Quebec, which has been at the forefront of developing mass timber, will be adopting revisions to its province-wide building codes that will allow the product to be used more widely. With any luck, she said, this will prod others to do the same.

“We’re hoping to it will be further accepted as people become familiar with it,” she said.

(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)