Section 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.Wash. Admin. Code § 246-359-230
Statutory Authority: RCW 70.114A.081. 99-03-065, § 246-359-230, filed 1/18/99, effective 2/18/99.