“Once upon a time, 2-by-4s really were 2 inches by 4 inches,” Stephens says. Without the rough edges, what went in as a 2-by-4 planks of rough-sawn wood is now a tongue-tripping 1.5-by-3.5, having lost approximately ¼-inch on all sides to the planer and drying processes. The real shrinkage, however, comes when the “rough-sawn material” is sent to a planer, which rubs the surface of the wood down into the smooth shapes you can purchase at a hardware store. Through the drying process, the boards naturally shrink, as moisture leaves the beams. Additionally, heating helps remove bugs and other detritus. What’s more, by accelerating a piece of wood’s natural warping process, the lumber industry can deal with any inconsistencies before it gets to you, the consumer. But, Stephens says, “drying gets a lot of those problems out of the way.” By speeding up the process, manufacturers cut down the time it takes to turn a tree into a plank.

Wood is hygroscopic, so it adjusts its internal moisture to match the external moisture of its environment. Softwoods like pine, which is common for beams and planks, are baked below 240 degrees. Sometimes, the material is run through a wood kiln. A typical plank is air dried on site, cut up into boards, and dried again. And moist wood-called “green lumber”-is prone to bending and warping. Those cants, just moments ago part of a living tree, are moist. “A cant is the biggest piece you can get out of a log.” “ is round, but saws cut straight,” Stephens continues. “And then you cut that tree up into chunks” called cants, according to Stephens. To create a beam or plank of wood, one must start by chopping down a tree. But the origins of the 2-by-4 are more complicated than an old-timey lumberjack deciding to round up. The phrase 2-by-4 “rolls off your tongue a helluva lot easier” than the truth, he says. “Two by four is a colloquialism,” says Mark Stephens, the vice president of Woodworkers Source, an Arizona-based company. The same is true for most other wood cuts, which are all systematically smaller than their names would suggest. You’d be forgiven, then, for answering the question “What size is a 2-by-4?” with “2 inches by 4 inches.” But it turns out, you’d be answering this particular riddle wrong. For example, the answer to the legendary not-joke “Who’s buried at Grant’s Tomb?” is, quite obviously, “Grant.” There’s an entire subgenre of American humor derived from carefully placing the punchline into the question itself. Edge of six cedar two by four lumber boards stacked on white background.

1.5 inch actual size