Building Material Tip
Dimensional Lumber
When you're picking out boards at the store, remember that a "two-by-four" isn't actually two inches by four inches. This is called its "nominal" size. The real, or "actual," size is smaller because the wood is planed smooth and dried after it's first cut. A two-by-four is actually about one and a half inches by three and a half inches. A "one-by-six" is really about three-quarters of an inch by five and a half inches. Knowing this real size is super important when you are measuring for a project. If you plan for a two-inch thick board and it's only one and a half, your project could end up wobbly or not fit together right. Always check the actual dimensions on the label or with a tape measure before you buy.
Before you start building, lay all your boards out and look at the edges. You'll see lines that look like rings or curves; this is the wood grain. For most projects, you want the curved part of those rings, called the "crown," to point up. When you nail the board in place with the crown up, the weight of your project will help press it down flat over time. If the crown is pointing down, it can sag and create a dip or a weak spot. Taking a moment to "crown" your lumber is a simple trick that makes shelves stronger, keeps fences straighter, and helps decks last longer.
