2x4

2x4 is a widely used dimension in North American construction referring to a piece of dimensional lumber. The term is nominal, originating from the lumber mills’ original rough cut size. In finished form, a 2x4 typically measures 1.5 inches in thickness and 3.5 inches in width, with the length varying in standard stock increments.

Common uses for 2x4 lumber include wall framing, where they serve as studs, as well as structural bracing, sill plates, and headers. They are produced in a range of lengths, with 8, 10, 12, 14, 16, 18, and 20 feet being typical. In construction, 2x4 studs are commonly spaced 16 inches on center, though spacing can vary.

Materials and grades vary by species and intended use. Softwoods such as pine, spruce-pine-fir (SPF), and southern yellow pine are common. Lumber is sold in rough or surfaced forms, and may be kiln-dried to reduce moisture content. Some 2x4s are pressure treated for exterior framing or ground contact to resist decay and insects. Grades reflect structural strength and appearance, and are indicated by grade stamps on the finished stock.

Variations and related sizes include 2x6 or larger members and specialized products such as laminated veneer lumber. While the nominal 2x4 remains standard for many interior applications, advances in building methods and alternative materials continue to influence its use in modern construction.