Commercial lumber is sold as boards and planks by dimension sizes. However, the dimensions do not match the actual lumber sizes. For example, a 2 X 4 in. (50.8 X 101.6 mm) pine board is cut to the full 2 X 4 in. (50.8 X 101.6 mm) at the sawmill. This is called the nominal dimension. The nominal dimensions are reduced because of shrinkage and surfacing in both width and thickness. For example, the actual dimensions of a nominal 2 X 4 in. (50.8 X 101.6 mm) are 19/16 X 39/16 in. (39.7 X 90.5 mm). Lumber that is not surfaced is referred to as rough-sawn. Most lumber for construction is surfaced (dressed) to a standard net size which is less than the nominal (name) size. Surfaced lumber is lumber that has been smoothed or sanded on one side (S1S), two sides (S2S), one edge (S1E), two edges (S2E), or on combinations of sides and edges (S1S1E, S2S1E, S1S2E, or S4S).
cost. For example, if the cost of pine lumber is $400 per 1,000 board feet, then the cost of a 2 in. x 6 in. x 10 ft (50.8 x 152.4 x 3048.0 mm) piece would be:
— (2 in. x 6 in. x 10 ft) x = $4 12 1000