Lumber & Wood

Dimensional lumber sizes under the American Softwood Lumber Standard (DOC PS 20) define the difference between rough-sawn 'nominal' green lumber designations and finished 'actual' Surfaced 4-Sides (S4S) dry dimensions. A standard 2×4 measures exactly 1.5 × 3.5 inches (38 × 89 mm) following planing and kiln drying.

Structural Glued Laminated Timber (Glulam) under ANSI A190.1 is an engineered heavy timber beam manufactured by face-bonding individual 2x softwood dimensional lumber laminations with structural adhesives. Featuring standardized widths of 3-1/8", 5-1/8", and 6-3/4" and depths in 1.5-inch increments, Glulam beams support spans exceeding 100 feet.

The Janka Wood Hardness Scale is standardized under ASTM D143 (and ISO 3350) by measuring the exact force (in pounds-force / lbf or Newtons) required to embed an 11.28 mm (0.444 in) steel ball to half its diameter into a wood sample, establishing the international benchmark for hardwood flooring and lumber dent resistance.

Structural wood panels including softwood plywood and Oriented Strand Board (OSB) are standardized under Voluntary Product Standards DOC PS 1 and PS 2. Sized in standard 4×8 ft (1219×2438 mm) sheets, panels are classified by 'Performance Category' thickness with a -1/32" decimal reduction, where a nominal 1/2" panel measures 15/32" (0.469" / 11.9 mm).