Section SPS 327.34 - Wood frame walls Unless designed through structural analysis, wood frame walls shall comply with the following requirements:
(1) STUD CONFIGURATION. Studs in the exterior walls shall be placed with the wide faces perpendicular to the plane of the wall. Note: See s. SPS 327.28 for requirements on treating wood for decay and termite resistance.
(2) TOP PLATES. (a)General. Except as allowed under par. (c), top plates shall be provided and configured as follows: 1. Studs at bearing walls shall be capped with double top plates.2. End joints in double top plates shall be offset at least 2 stud spaces.3. Double top plates shall be overlapped at the corners and at intersections of partitions.4. The plate immediately above the stud may have a joint only when directly over the stud.(b)Notching and boring.1. When piping or ductwork is placed in an exterior wall or an interior load-bearing wall, such that at least half of the top plate is removed, the plate shall be reinforced with a steel angle at least 2 inches by 2 inches by 20 gauge thick. Note: 20 gauge is approximately 0.036 inch.
2. The steel angle shall span the gap and extend at least to the midpoint of the adjacent stud spaces.3. Other equivalent materials may be used in accordance with s. SPS 327.20.(c)Exceptions.1. A single top plate may be used in place of a double top plate provided a rafter is located directly over the studs and the plate is securely tied at the end joints, corners and intersecting walls. Joints may occur in single top plates only when directly over a stud.2. A continuous header, consisting of two 2-inch members set on edge, may be used in lieu of a double plate if tied to the adjacent wall.(3) WALL OPENINGS. (a)Headers. Where doors or windows occur, headers shall be used to carry the load across the opening.(b)Header support. Headers in bearing walls shall be supported in accordance with the following:1. Headers 3 feet or less in length shall be directly supported on each end by one of the following: a. The single common stud and a shoulder stud.b. The single common stud with a framing anchor attached.2. Headers greater than 3 feet but less than or equal to 6 feet in length shall be directly supported on each end by the single common stud and a shoulder stud.3. Headers greater than 6 feet in length shall be directly supported on each end by the single common stud and 2 shoulder studs.(4) NOTCHING. Notching and boring of columns or posts is prohibited unless designed through structural analysis. Studs shall not be cut or bored more than 1/3 the depth of the stud, unless the stud is reinforced.(5) PARTITIONS. Load-bearing partitions shall be placed over beams, girders, or other load-bearing partitions. Load-bearing partitions running at right angles to the joists shall not be offset from the main girder or walls more than the depth of the joist unless the joists are designed to carry the load.(6) POSTS AND COLUMNS. (a)General.1. Posts and columns shall be installed to resist imposed loads.2. Posts and columns shall bear directly over the middle 1/3 of a footing.3. Posts and columns shall be restrained at the top and bottom to resist displacement.4. All columns shall be positively attached to the beams they support using clips, straps or saddles.5. Posts and columns that use a height adjustment mechanism shall have the mechanism imbedded in concrete or permanently disabled after installation.(b)Bearing surface. Posts and columns shall have a steel bearing plate affixed to one or both ends to distribute any applied loads and to prevent fiber crushing of any structural member being supported.(c)Steel posts or columns. Steel posts or columns shall be sized according to one of the following methods:1. Manufactured columns shall follow the manufacturer's testing and listing.2. Columns made of steel stock, not meeting the requirements of subd. 1., shall follow a nationally accepted design specification or the size shall be determined through structural analysis or load testing.(d)Wood posts or columns. Wood posts or columns shall be sized according to Table 327.34 or the size shall be determined through structural analysis or load testing.(7) FOUNDATION CRIPPLE WALLS. (a) Foundation cripple walls shall be framed with studs at least as large as the studs above.(b) When more than 4 feet in height, cripple walls shall be framed with studs needed for an additional floor level.(c) Cripple walls shall be sheathed on at least one side for its entire length with a wood structural panel that is fastened to both the top and bottom plates or the cripple walls shall be constructed of solid blocking.(d) Cripple walls shall be fully supported by a continuous foundation. Table 327.34
WOOD COLUMNS
Wood Nominal Size | Cross Section Area | Height (feet) | Allowable Load (pounds) |
4" x 4" | 12 1/4" | 8 | 4,900 |
10 | 3,100 |
12 | 2,150 |
4" x 6" | 19 1/4" | 8 | 7,700 |
10 | 4,900 |
12 | 3,400 |
6" x 6" | 30 1/4" | 8 | 30,000 |
10 | 18,900 |
12 | 13,300 |
Wis. Admin. Code Department of Safety and Professional Services SPS 327.34
Adopted by, EmR1703: emerg. cr., eff. 2-6-17; CR 17-017: cr. Register March 2018 No. 747, eff. 4/1/2018This Table is based on a modulus of elasticity or E of 1,000,000 psi and a fiber bending strength or Fb of 1,000 psi.