A LEXICON OF LUMBER

Studs: They're a lot easier to find when the room looks
like this. Otherwise, buy a good studfinder.

Watch any of those popular home-improvement shows on television, and you’ll ’ll be assaulted by a barrage of arcane carpentry terms. Given that it’s a sort of badge of honor among do-it-yourselfers to know their studs from their stools—as it were—I humbly offer the following primer:

•  Stud. We’ll start with an easy one, what? Anyone who’s ever hung a picture knows that a stud is one of the vertical 2x4s that make up the wall framing. They’re usually spaced 16” apart (or “on center”, as architects and builders like to put it).  However, knowing what a stud is is one thing; finding one is another. A sharp rap on the wall with a knuckle will do for the experienced; for the rest of us, an electronic studfinder is a better choice.

Pressure treated 2x4 lumber as now
used for mudsills in place of redwood.
Some is dark brown; some is greenish;
some has telltale needle marks
like this does.

•  Mudsill. Like many carpentry terms, this one has a quaint Middle Ages ring to it. It refers exclusively to the special piece of 2x4 or 2x6 lumber that’s placed directly on top of the concrete foundation wall—a location highly vulnerable to moisture and insect attack. Prior to World War II, the mudsill was usually made of redwood to resist the effects of termites and rot. Because redwood is so pricey now, it's been replaced by pressure treated lumber. This is just ordinary Douglas Fir with a preservative injected into it, which explains why it has all those needlemarks.

A header beam carries the load of upper floors or roofs
whereever there is an opening in a wall,
such as a door or window.

•  Joist. Now here’s a word with a nice creaky sound that’s perfectly suited to its meaning. A joist is one of the narrow beams that supports your floor. Like studs, joists are spaced 16” on center; they range in size from 2x6 to 2x12, depending on the load they carry and the distance they span. And by the way—it’s usually not the joist that creaks, it’s a piece of the subflooring rubbing against against its neighbor.

•  Header. This is the elusive critter you hunt for when you’re hanging curtain rods. Most people have heard of it, but because it’s hidden by drywall, they’re not quite sure what it looks like or what it’s for. A header is simply a heavy wooden beam—nowadays usually a 4x12—that bridges a door or window opening and carries the load above it. 

The part of the rafter that stick out past the exterior wall
is variously known as a lookout, an outlooker,
or a rafter tail, depending on where
the carpenter comes from.

•  Stool.  Here’s a puzzling one. Stool is the technical term for that piece of wood across the bottom of a window opening—the one any normal person would call a sill. In the building trades, however, sill only applies to the stool’s counterpart on the outside of the wall.  Oh, and that little piece of trim beneath the stool?  Why, that’s the apron, of course.

•  Outlooker, rafter tail, lookout. Carpentry terms vary a lot by region—a fact that’s nowhere as evident as in these terms. All of them refer to the part of the rafter that projects past the outside wall and is visible under the eaves. While they’re all charming terms, “rafter tail” is my favorite, because it jibes delightfully with the carpenter’s name for the wee notch in the rafter where it crosses the outside wall: birdsmouth cut.

•  Ledger. Maybe you’ve already guessed that this term doesn’t relate to bookkeeping—something both contractors nor architects are famously bad at. In carpentry, a ledger is a piece of 2x lumber that’s attached to the face of a wall to support some other structure—the floor of a deck, for example.  I suppose it derives from “ledge”, which is sort of what it creates. So why isn’t it just called a “ledge”? 

Look, I just write about this stuff, I don’t invent it.