Rough lumber, surfaced lumber (dressed), worked lumber, shop and factory lumber and yard lumber.
Sawn, trimmed and edged lumber. The faces are rough with saw marks.
Rough lumber smoothed by surfacing machines. Subcategories based on the number of sides and edges that have been smoothed.
- S1S - Surfaced on 1 Sides
- S2S - Surfaced on 2 Sides
- S3S - Surfaced on 3 Sides
- S4S - Surfaced on 4 Sides
- S1E - Surfaced 1 Edge
- S2E - Surfaced 2 Edges
- S1S1E - Surfaced 1 Side and 1 Edge
- S1S2E - Surfaced 1 Side and 2 Edges
Note that S4S lumber planed and surfaced all four sides will be noticeably less than in its nominal dimension.
Surfaced lumber that has been matched and patterned.
Shop and Factory Lumber
Millwork lumber - used for molding, door jambs and windows frames.
Structural Lumber or Yard Lumber
Yard lumber used for house framing, sheathing, concrete forms.
Yard lumber or structural softwood lumber is subdivided in
- Boards - no more than 1 inch thick and 4-12 inches wide
- Planks - more than 1 inch thick and more than 6 inches wide
- Timbers - width and thickness greater than 5 inches