MPR: Minnesota Sawmill Turning Green

Minnesota Sawmills Turning "Green"
By Leif Enger
December 22, 1997

The wood-products industry is a Minnesota giant. There are hundreds of sawmills in the state, creating thousands of jobs - and thousands of tons of slabwood, sawdust and refuse each year. Now, a practice called "green dimensioning" is gaining proponents in the state; they say it conserves wood, saves energy, and moves jobs to the outstate area.

IMAGINE A 1,000-POUND LOG; an oak log, say, stacked with its brethren outside any of Minnesota's 800 sawmills. The log appears round and perfect; once it's debarked, you'd assume very little would be wasted.

And you'd be wrong. First the log is slabbed - turned from a cylinder into a square. The leftover slabs are bark on the outside with a thick crescent of clean wood within; they'll be sold as cheap firewood or thrown away. The squared log is then sawed into boards. The sawblades are thick - and when the dust settles, your thousand pound log has turned into 500 pounds of rough planks, and 500 more of stuff almost nobody wants.

Bartz: These hardwood trees are growing up for 100, 120 years, and then we cut 'em down and saw 'em up with thick-kerf saws. And the waste through this whole process, from the stump to the finished furniture, just blew my mind.

Bob Bartz owns Palisade Supply, an Aiktin County sawmill. Since 1990 he's been working to implement a new, more efficient type of milling known as "green dimensioning." It's deceptively simple: once a log is sawed into raw (or green) boards, most mills kiln-dry those boards - knots, defects and all. At Bartz's mill, the green boards are crosscut into smaller pieces. Defects are cut out. Once these pieces are dried, the result is a shorter but higher-quality board. No energy's been wasted drying defective wood; none will be wasted shipping defective wood. Most rewarding of all, Bartz says, you get to intercept good wood on its way to the trash heap.

Bartz: This is white ash paneling and white ash flooring. It's gonna be beautiful. This came out of a slab. This is what a mill normally throws away, or burns for firewood, or puts in a chipper for paper chips. We make flooring out of a slab.

It's estimated green dimensioning - especially when practiced with new, thin-bladed saws - can save 15 to 20 percent of the wood in a log. It can also squeeze high-value products from scrubby, small-diameter trees. That's important, according to Department of Natural Resources marketing specialist John Krantz, because US hardwood forests aren't what they used to be.

Krantz: We're in a situation in the United States where our forest resources are limited. And we have to figure out a way to manufacture more product out of the same resources. That's where green dimensioning fits in, and I see this becoming very popular in the next five to ten years, throughout the United States.

But there are obstacles to green dimensioning - reasons that in a state with 800 sawmills, fewer than six are employing the practice. Bartz and others have found while they might have a good product, selling it is another matter. That's because lumber is traditionally sold in lengths of eight feet or more; then cut to size by the customer - cabinet or furniture makers, for example.

Krantz: So, all of a sudden, you come along with a truckload of pieces that are mixed - mixed length and mixed sizes - and nobody really knows how to handle that. The distribution system isn't set up to handle and market that kind of wood.

Timber-market specialists like Krantz believe if green dimensioning catches on, it'll be because of the market itself. Loggers in some parts of Minnesota are now paying triple the 1990 price for timber on the stump. As demand for certain woods outstrips supply, the situation in this country could begin to resemble that in forest-poor Asia and Europe, where green dimensioning has been standard practice for years.

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