What are the actual dimensions of lumber?
What are the actual dimensions of lumber?
Common Dimensional Lumber Sizes
| Dimensional Lumber: Nominal Size vs. Actual Size | |
|---|---|
| Two-by-four or 2 x 4 | 1 1/2 inches x 3 1/2 inches |
| Two-by-six or 2 x 6 | 1 1/2 inches x 5 1/2 inches |
| Two-by-eight or 2 x 8 | 1 1/2 inches x 7 1/4 inches |
| Two-by-ten or 2 x 10 | 1 1/2 inches x 9 1/4 inches |
What is true dimensional lumber?
Dimensional lumber is cut to a specific length, width, and depth. However, there is a difference between the nominal size (what the lumber is referred to) and the actual size.
Why is lumber not true to size?
Maybe you’ve noticed that lumber sizes are often misleading. The “nominal” cross-section dimensions of a piece of lumber, such as 2 X 4 or 1 X 6, are always somewhat larger than the actual, or dressed, dimensions. The reason is that dressed lumber has been surfaced or planed smooth on four sides (called S4S).
What is the difference between nominal and actual sizes in lumber?
The simple answer is the nominal measurements were derived from a board’s size before it has been dried and planed smooth (surfaced) on all 4 sides. The actual measurements are the final dried and surfaced size.
What is the actual size of a 2×3?
38 x 64 mm
Nominal vs. Actual Measurements of Dimension Lumber
| Nominal Size | Actual Size |
|---|---|
| 2 x 3 | 1 1/2 x 2 1/2 inches (38 x 64 mm) |
| 2 x 4 | 1 1/2 x 3 1/2 inches (38 x 89 mm) |
| 2 x 6 | 1 1/2 x 5 1/2 inches (38 x 140 mm) |
| 2 x 8 | 1 1/2 x 7 1/4 inches (38 x 184 mm) |
When did lumber dimensions change from actual to nominal?
Early concepts called for rough lumber to be of full nominal size, often in the dry condition. After World War I, the increasing demand for construction lumber led to the first national size standard in 1924. This was revised in 1926, 1928, 1939, and 1953, while still another revision is proposed for adoption in 1964.
Why isn’t a 2×4 actually 2×4?
Now, most timber is milled and planed to give it a little more of a finished look, and a little more of a consistent size and profile. Because of this extra milling, a 2×4 no longer measures a full 2 inches by four inches. Instead, a 2×4 is really only 1 1/2″ by 3 1/2″.
What are the dimensions of a 2×3?
What does 2×3 mean in measurement?
Common Lumber Dimensions
| Nominal Size | Actual Size |
|---|---|
| 1×10 | 3/4″ x 9-1/4″ |
| 1×12 | 3/4″ x 11-1/4″ |
| 2×2 | 1-1/2″ x 1-1/2″ |
| 2×3 | 1-1/2″ x 2-1/2″ |
When did dimensional lumber change size?
During the late 1940s or early 1950s, builders in many areas of North America switched to planed 2x4s that measure 1.5″ x 3.5″. Here in rural Vermont, builders are still sometimes building new homes with rough-cut full-dimension 2x4s (or, more commonly, 2x6s) cut on a bandsaw mill.
When did they stop using true 2×4?
Size standards, maximum moisture content, and nomenclature were agreed upon only as recently as 1964. The nominal 2×4 thus became the actual 1½ x 3½, imperceptibly, a fraction of an inch at a time. It was a 34 percent reduction in actual volume; as those in the trade would say, it’s “selling air.”
When did a 2×4 get smaller?
