Lumber which comes from conifer trees (needle-shaped leaves that stay green year-round). Softwoods can be classified as dry (less than 19 percent moisture) or green/unseasoned (greater than 19 percent moisture)

Size

Softwoods are smaller than the size they are named. The thickness of the wood is the smaller of the two measurements; the face width is the larger. Each is measured in inches (The length is measured in feet, and is actual size).

Thickness

Less than 2 inches
Dry: subtract 1/4 inch
Green: subtract 7/32 inch
2 to 8 inches
Dry: subtract 1/2 inch
Green: subtract 7/16 inch
Face Width
2 to 4 inches
Dry: subtract 1/2 inch
Green: subtract 7/16 inch
5 to 8 inches
Dry: subtract 1/2 inch
Green: subtract 3/8 inch
8 to 16 inches
Dry: subtract 3/4 inch
Green: subtract 1/2 inch

Grading

There are two different classification systems for softwoods that have some overlap. First:

Rough Lumber
Sawn, trimmed, and edged, but with rough faces.
Surfaced Lumber
Rough lumber that has had some number of sides and edges smoothed by a surfacing machine. The system is SnSmE, where m and n are the number of sides and edges surfaced, respectively.
Worked Lumber
Surfaced lumber, that has also been shiplapped, patterned, and/or matched.
The second classification system:
Shop and Factory Lumber
Millwork used for moldings, door jambs, and window frames.
Yard Lumber
Also known as structural lumber, used for framing, sheathing, and concrete forms.
Yard lumber is subdivided into:
  • Boards - no more than 1" wide and 4-12 inches thick.
  • Planks - over 1" thick and more than 6" wide.
  • Timbers - more than 5" in each dimension

Log in or register to write something here or to contact authors.