WAC 246-359-230
Wall framing for wood framed construction. (1) Exterior walls and interior partitions must be framed as
follows:
(a) Studs must be minimum two-by-four wood, Hem-Fir stud
grade or better, spaced not more than sixteen inches on center,
support no more than one ceiling and one roof, nor exceed eight
feet in height for exterior walls.
(b) Studs must be placed with their wide dimension
perpendicular to the wall. Not less than three studs must be
installed at each corner of an exterior wall.
(c) Studs must be capped with double top plates installed to
provide overlapping at corners and at intersections with other
partitions. End joints in double top plates must be offset at
least forty-eight inches.
(d) Studs must have full bearing on a plate or sill not less
than two inches nominal in thickness having a width not less than
that of the wall studs.
(2) Headers. All openings four feet wide or less in bearing
walls must be provided with headers consisting of either two
pieces of two-by-eight Hem-Fir #2, or better, placed on edge and
securely fastened together or one piece of four-by-eight Hem-Fir
#2 or better. All openings over four feet and up to eight feet
wide in bearing walls must be provided with headers consisting of
two pieces of two-by-twelve Hem-Fir #2 or better, placed on edge
and securely fastened together, or one piece of four-by-twelve
Hem-Fir #2 or better.
(3) Wall bracing. Exterior walls must be braced with one of
the following methods:
(a) Wood boards of five-eighths inch net minimum thickness
applied diagonally to the studs and face nailed with 2-8d common
nails per stud.
(b) Minimum forty-eight inch width of wood structural panel
sheathing (plywood) with a minimum thickness of three-eighths
inches applied vertically at each corner. Provide solid blocking
at all edges not supported by studs and secure to studs with 6d
common or deformed shank nails spaced at six inches on center at
edges and twelve inches on center at intermediate supports.
Sheathing must extend from treated plate through double top
plate.
(4) Where plumbing, heating or other pipes are placed in
studs, a metal tie not less than sixteen galvanized gauge and one
and one-half inches wide must be fastened to each plate across
and to each side of the opening.
[Statutory Authority: RCW 70.114A.081. 99-03-065, §
246-359-230, filed 1/18/99, effective 2/18/99.]