Structurally, wood may be used for joists, posts, columns, beams, and trusses. It may also be laminated into structural shapes, such as columns, beams, rigid frames, arches, vaults, with fiberboard, particle board, plywood, or wood decking (plain or laminated) to form composite panels. Wood may be exposed and finished for interior or exterior use. It may be purchased pressure-treated to provide resistance to moisture, rot, or exposure.

Structural lumber is stress-graded for bending, tension parallel to the grain, horizontal shear, compression perpendicular...