Unlike other building materials, dimension lumber is available only in
a very limited number of sizes. Typical low-rise building constructio
n uses common ''two-by'' lumber ranging in size from nominal 2 x 4 to
2 x 12 (38 x 89 to 38 x 296 mm). The implications of sizing up to the
next available discrete lumber size on the reliability of wood members
in flexure are reported in this paper. Consideration is given to both
strength and deflection serviceability limit states and the new load
and resistance factor design (LRFD) specification for wood constructio
n.