Baby, it’s cold outside. So we thought we’d revisit one of the hottest Lab Notes posts ever published. The debate over how to stack firewood must still not be settled, as this post consistently ranks in the top-viewed list. Have a read and then decide for yourself: bark up or bark down?
“You can tell a lot about a person from his firewood stack.”
So declared Lars Mytting in a New York Times piece about the debate among firewood-splitters in Norway. The central question remains: bark up or down?
Mytting has ignited a national passion for Norwegian wood in books and on television. Given that the audience in Norway seems split 50/50 on proper firewood stacking technique, we put the question to a couple of our Forest Service experts.
“It would be humorous if it was all semantics.” says Mark Knaebe, natural resources specialist with the FPL Forest Products Marketing Unit. But it does make a difference, he says. If split wood is stored outdoors, stacking it with the bark side down can allow water to collect in the u-shaped trough. This moisture retention can prolong drying and accelerate decay, says Knaebe. Stacking it outdoors with the bark-side-up, on the other hand, can help protect the pile of wood below from rain and other weather.
Many people store wood in a shed or some other type of shelter. In climates with even moderate precipitation, having a roof over your wood is advantageous. In this case, the bark up-or-down debate becomes fairly inconsequential, says Knaebe. With even a slight breeze moving through the shelter, he says, drying occurs considerably faster than in a dead-air space.
Whether stacking it inside or out, many people lay a few small logs or lumber on the ground perpendicular to the first row of stacked wood. This allows for better air-flow and reduces the potential for bacterial or fungal infestation due to close proximity to the ground, says Jan Wiedenbeck, Research Forest Products Technologist with the U.S. Forest Service Northern Research Station.
“I also wonder if the bark, when on top, might protect unsheltered wood from long-term photo-degradation?” says Wiedenbeck. “Sunlight can certainly affect checking and splitting in wood, but does it affect Btu’s?”
Knaebe, a wood energy expert, responds that while ultra-violet light can indeed destroy lignin, which has a higher Btu than the rest of wood’s constitutive parts, it wouldn’t be enough to significantly affect actual thermal output.
In the end, an answer to the “bark up or bark down” question seems to be: it depends. When storing split wood under shelter, where air-flow becomes more important, bark up or bark down seems to be a matter of personal preference. There is also the question of ease of handling, says Wiedenbeck. Bark down, she says, means wedge-side-up makes it easier to pick off the pile.
To see how firewood compares to other sources of energy, take a look at FPL’s ever-popular Fuel Value Calculator.