WOOD BEAM SIZINGTM

BEAMS

WBS uses beams in the general sense to mean any approximately horizontal load bearing structural framing member. In casual usage, beams will include girders, joists and rafters.

For lumber grading, beams are defined as sawn lumber 5-inches or larger in both width and depth with separately graded strength values to account for the increased number of knots and splits.

Compare with dimension lumber - 4-inches or less in thickness.


The NDS further separates beams and stringers from posts and timbers.

A post is approximately square. The depth of a beam is 2-inches or greater than its width.   For example: