By LUCY SCHROEDER
Capital News Service
LANSING — You may recycle in your home, but did you know the building itself can be recycled?
A group of researchers at Michigan State University studying the science of domicology — the term they use to describe the policies, practices and consequences of abandoned structures — are examining how wood from abandoned buildings can be reused.
The average Michigan home holds about 6,000 board feet of lumber, enough to fill two school buses, according to George Berghorn, an assistant professor of construction management at MSU. And the state has 244,000 abandoned homes.
The lumber in abandoned buildings includes a mix of aesthetic products such as doors, siding and windows that can be sold as salvage. However most of the wood in homes is structural material used to construct the frame of a building — the support for the walls and roof.
Robert Falk, a scientist with the U.S. Forest Products Lab in Madison, Wisconsin, has tested structural wood to see if it can be safely reused as structural wood in other buildings.
Structural wood receives a grade that describes its quality and best use. Once wood has been nailed and cut, it may not be sound enough to be reused structurally, so it must be tested and regraded.
Falk and his colleagues attempted to work with the wood and deconstruction industry to develop a new system for grading. But industry officials have decided that it must be re-graded using existing standards for new wood, he said.
Because of the high cost to have the wood inspected and re-graded, deconstruction and reclaimed wood industries need large stockpiles of reclaimed lumber to make it worth the expense, Falk said.
For a lot of people in Detroit, re-grading structural lumber is on the radar but not a top priority, said Jeremy Haines, executive director of Reclaim Detroit, a nonprofit deconstruction organization. Right now, Reclaim Detroit lacks a system to grade reclaimed lumber.
Some researchers envision other ways to reuse lumber in cross-laminated timber made by taking long sticks of lumber and sticking layers together, alternating 90 degrees.
Demand for cross-laminated timber products has grown, said Kris Speckler, a heavy timber specialist with Structurlam, a mass timber manufacturer in British Columbia, Canada. It can be used as a load-bearing wall that doesn’t require additional wood framing.
It is lighter, cheaper and less wasteful than concrete and steel, Speckler said. Cross-laminated timber panels are also easier and quicker to erect because the structural support and wall can be constructed with the installation of one panel.
Structurlam gets its wood from trees damaged by pine beetles in the Pacific Northwest, Speckler said.
The company has constructed more than 300 buildings with cross-laminated timber since 2011. It’s ideal in multi-story buildings — the company has built one 18 stories tall, Speckler said.
To make cross-laminated timber from reclaimed lumber, the surface must allow the adhesive to bond, Speckler said. Reclaimed lumber must be sent through a sawmill to fit it to the standard size and prepare it to accept adhesive.
But Speckler said he thinks that isn’t the best use of reclaimed lumber.
“Large timbers can be really beautiful,” Speckler said. He sees structural wood being reused for more decorative purposes.
Falk said that builders worry that the supply of reclaimed material isn’t consistent in quantity or size. To make it feasible, there need to be standards to deliver uniform quality for manufacturers, he said.
There may be other options to reuse such wood, Berghorn said, including manufacturing wood pellets to heat homes.
In northern Michigan, for example, many homes that lack access to natural gas, according to a study that Berghorn was a part of. Most heat with propane, an expensive fuel source.
Converting these homes to burning wood pellets would give their owners a way to use cheaper fuel and create a market for reclaimed wood.
Other options for wood as a fuel source include torrefied wood, a coal substitute that is better for the environment and equivalent in energy value to coal.
Another possibility for wood from old homes is biorefinery, which is the process of breaking down the fibers in plant materials into fuels and other useful chemicals.
That could be an option for reclaimed wood because it would just be ground up anyway, Falk said.
But, Berghorn said, those products are way in the future because more research is needed to make them efficient.
For now, Falk said, the deconstruction industry may be best for serving local communities and reusing salvaged wood for non-structural applications.
Lucy Schroeder writes for Great Lakes Echo.