Understanding Wood
Estimated Read Time: ~6 minutes
Fire crawled over the wood in the fire pit in a hypnotic, magical flicker that draws people of all ages together. It draws breath as the wood burns; it generates heat that pushes us away on a hot night or pulls us in closer on a cold one. Its smoke rises and dances through the canopy above, disappearing into open air. Smoke clings to our clothing and senses in legendary fashion.
Our world revolves around wood like no other material. It has shaped our lives more than we give it credit for. It’s everywhere. All people depend on it. At one time we relied on it for heat and cooking—the most basic of needs. Our technology has evolved, our tools have improved, and machines now cut and shape wood in ways our ancestors could never have imagined.
This is our world. We can walk into a lumber yard and buy any species of kiln‑dried lumber we want. It has never been this easy to get wood in human history. It comes in flat, milled boards that make great material to build with. But to build with wood, you must respect the fact that it wasn’t invented for woodworkers or designers. It was a tree. It was alive. It has memories, character, and style, and it can be the crankiest, most stubborn stuff to work with if you don’t respect its origins. But the results can be amazing. In our engineered world of metal and plastic, wood remains elemental and organic. Humans will always be drawn to it.
As a tree grows from a sapling, it reaches upward—some species taller than others. It survives animals grazing, bugs burrowing, birds pecking, squirrels climbing, and fires burning. It endures long winters, spring flooding, dry summers, early falls, and the constant push of the wind. Trees evolved to survive all of this. They’re built tough, whether they grow in the tropics or on the edge of the Arctic.
But no matter the climate, they share one thing: they grow heavy trunks and limbs, and they grow tall. Gravity pulls at that weight. The tree needs light, so it reaches. Gravity never stops, so the tree adapts and grows despite the force. This is why wood is strong—and why it’s often reactive.
If a tree grows straight and avoids wind damage, the wood will be lovely to work with. But that’s rare. Trees reach for light, and where the seed germinates isn’t always where the light is. So the tree grows at an angle to survive. Look around next time you’re in a forest—you’ll see it everywhere.
But gravity doesn’t change. The tree grows deep roots and holds the earth, leaning like a ladder against a wall. A full‑grown tree can weigh tons. Its cell structure develops to support that angle — but hardwoods and softwoods do it differently. In hardwoods, the upper side of the leaning trunk forms tension wood that pulls the tree upright. In softwoods, the lower side forms compression wood that pushes the tree up. Two different strategies, same result: a tree that can have a wildly off‑center center of gravity and still grow for a hundred years.
Gravity pulls. The tree pushes back. Year after year it grows taller, reaches farther, thickens its trunk, and adds weight. And still it stays in equilibrium.
Then one day a person comes along. The tree is cut, milled, dried in a kiln, shipped to a lumber yard, and sold to a woodworker. Now the tree is boards—but the cellular structure is still locked in, even though gravity no longer plays a role. The board sits on the bench, straight as a banana, and the woodworker shakes their head, knowing this wood will fight back. The wood is still countering the gravity it grew under. That worked when it was a tree. But once the trunk is cut, the fibers release tension as the blade moves through them.
As a woodworker, it’s my job to deal with this.
The point of all this is simple: wood was a tree. It was alive. It has memories, character, and style, and it can be stubborn if you don’t respect its origins. When working with wood, we need to understand that it behaves—and why. You don’t need deep scientific knowledge to build with it. You just need to respect where it came from and remember that every tree has its own story ingrained deep in its soul.
Wood is made of cells that absorb water—sometimes at different rates. It dries out. It can crack. Its grain reverses. It carries scars. It lived a life. So read the wood and understand what it’s doing. And if you’re not sure what’s going on, remember: it’s wood. There’s always another board.
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