Dimensional Lumber
Softwood lumber milled to standardized widths and thicknesses (2×4, 2×6, 2×8, etc.) for structural framing. Surfaced on four sides (S4S) and sold in standard lengths of 8 to 24 feet.
In Detail
Dimensional lumber is the backbone of wood-frame construction. It includes boards (1× nominal), dimension lumber (2×–4× nominal), and timbers (5×5 and larger). All dimension lumber is sold by nominal size but cut to actual size: a 2×4 is actually 1.5" × 3.5". Common species groups: SPF, Douglas Fir-Larch, Southern Yellow Pine, and Hem-Fir.