SPS 321.23(1) (1)Live and dead loads. All walls shall support all superimposed vertical dead loads and live loads from floors and roofs.
SPS 321.23(2) (2)Horizontal wind load. Walls shall be designed to withstand a horizontal wind pressure of at least 20 pounds per square foot applied to the vertical projection of that portion of the dwelling above grade. No wind load reduction shall be permitted for the shielding effect of other buildings.
SPS 321.23 History History: Cr. Register, November, 1979, No. 287, eff. 6-1-80.
SPS 321.24 SPS 321.24Exterior covering.
SPS 321.24(1) (1)General. The exterior walls shall be covered with a permanent weather resistant finish.
SPS 321.24(2) (2)During construction. During construction, wall cavity insulation may not be installed until a water-resistant covering is in place over the wall cavity and windows, doors and a roof with at least underlayment are installed.
SPS 321.24 Note Note: An example of acceptable water-resistant covering for a wall is foam sheathing with permanently taped joints.
SPS 321.24(3) (3)Flashing.
SPS 321.24(3)(a)(a) Corrosion-resistant flashing shall be installed in the exterior wall to prevent water from entering the wall cavity or coming in contact with the structural framing components.
SPS 321.24(3)(b) (b) The flashing shall extend to the surface of the exterior wall finish and prevent water from reentering the exterior wall.
SPS 321.24(3)(c)1.1. Any joints between 2 pieces of flashing that form a vertical joint shall be lapped a minimum of 6 inches and sealed.
SPS 321.24(3)(c)2. 2. Any joints between 2 pieces of flashing that form a horizontal joint shall be lapped a minimum of 2 inches and sealed unless otherwise specified by the flashing manufacturer.
SPS 321.24(3)(c)3. 3. Sealants used for flashing shall be exterior grade and shall be compatible with the materials being sealed.
SPS 321.24(3)(d) (d) Flashing shall be provided at all of the following locations:
SPS 321.24(3)(d)1. 1. At the top of all exterior door and window openings, unless using self-flashing windows that provide at least one inch of flashing around the opening, including the corners.
SPS 321.24(3)(d)2. 2. At the intersection of chimneys or other masonry construction with frame walls.
SPS 321.24(3)(d)3. 3. Under and at the ends of masonry, wood or metal copings and sills.
SPS 321.24(3)(d)4. 4. Continuously above all projecting wood trim.
SPS 321.24(3)(d)5. 5. Where porches, decks or stairs attach to a wall or floor assembly of wood frame construction.
SPS 321.24(3)(d)6. 6. At wall and roof intersections.
SPS 321.24(3)(d)7. 7. At built-in gutters.
SPS 321.24(3)(d)8. 8. Along the bottom of door openings that are elevated above-grade.
SPS 321.24 Note Note: Flashing placed along the bottom of a door opening that is elevated above-grade can subsequently accommodate adding a deck outside the door.
SPS 321.24(3)(e) (e) For a roof that intersects with an upper-lying head wall and rake wall, such as where a dormer is provided, the vertical metal flashing along the rake wall shall extend down the roof at least one-half inch past the vertical flashing on the head wall.
SPS 321.24 Note Note: A head wall as addressed in this paragraph intersects a sloping roof at a horizontal line along the top of a roof segment. A rake wall intersects a sloping roof along the side of a roof segment.
SPS 321.24(3)(f) (f) For a roof eave that intersects with a sidewall, the end of the roof flashing shall be installed so that it diverts water away from the sidewall and onto the roof or into the gutter.
SPS 321.24 Note Note: See s. SPS 321.26 (5) for additional flashing requirements with masonry cavity walls and s. SPS 321.28 (7) for additional flashing requirements with roofing.
SPS 321.24 Note Note: See s. SPS 321.26 (8) for further requirements relating to flashing for masonry.
SPS 321.24(4) (4)Water-resistive barrier requirements.
SPS 321.24(4)(a)(a) General.
SPS 321.24(4)(a)1.1. Exterior walls of wood or metal frame construction shall be provided with a water-resistive barrier from the highest point to the bottom of the permanent weather-resistant covering.
SPS 321.24 Note Note: Acceptable water-resistive barrier materials include polymeric-based house wraps and spray-applied water-resistive barriers installed per the manufacturer's instructions, #15 or greater asphalt-saturated felts that comply with ASTM D 226 for type I felt and extruded foam sheathing with permanently taped joints. Duct tape or similar will not result in a permanently taped joint.
SPS 321.24(4)(a)2. 2. Structural products with an integral water-resistive barrier may be approved by the department as a complete assembly.
SPS 321.24(4)(b) (b) Material compatibility. The water-resistive barrier material shall be compatible with the other materials in the wall with which it will come into contact.
SPS 321.24 Note Note: Spray-applied water-resistive barriers may not be compatible with foam plastic insulation.
SPS 321.24(4)(c) (c) Performance requirements.
SPS 321.24(4)(c)1.1. Polymer-based house wraps shall meet all of the following requirements:
SPS 321.24(4)(c)1.a. a. A water vapor permeability rating of 5 perms or higher when tested in accordance with ASTM E96.
SPS 321.24(4)(c)1.b. b. An acceptable water-resistance rating determined in accordance with ASTM D779, AATCC 127 or CCMC 07102.
SPS 321.24 Note Note: Asphalt-saturated felt or “tar paper" is not a polymeric-based house wrap.
SPS 321.24 Note Note: For more information on the water-resistance tests and their results, see the International Code Council Evaluation Services Acceptance Criteria AC 38.
SPS 321.24(4)(c)2. 2. Spray-applied water-resistive barriers shall be approved under the International Code Council Evaluation Services.
SPS 321.24 Note Note: For approval criteria, see ICC-ES acceptance criteria AC 212 or successor document.
SPS 321.24(4)(d) (d) Application.
SPS 321.24(4)(d)1.1. Horizontal seams in sheet or strip material shall be overlapped such that the upper layer extends over the lower layer at least 2 inches.
SPS 321.24(4)(d)2. 2. Vertical seams in sheet or strip materials shall be overlapped at least 6 inches.
SPS 321.24(4)(d)3. 3. Any rips, tears or voids shall be patched in accordance with subds. 1. and 2.
SPS 321.24(4)(e) (e) Penetrations.
SPS 321.24(4)(e)1.1. Penetrations caused by fasteners of the water-resistive barrier or the weather-resistant exterior covering do not require sealing.
SPS 321.24(4)(e)2. 2. Penetrations of 5 square inches or less with an annular space of no more than ½ inch shall be sealed with caulk or similar material.
SPS 321.24(4)(e)3. 3. Penetrations of greater than 5 square inches shall be flashed in accordance with sub. (3).
SPS 321.24 History History: Cr. Register, November, 1979, No. 287, eff. 6-1-80; r. and recr. Register, March, 2001, No. 543, eff. 4-1-01; CR 02-077: cr. (3) Register May 2003 No. 569, eff. 8-1-03; CR 08-043: am. (2), renum. (3) (c) to be (3) (d), cr. (3) (c) and (4) Register March 2009 No. 639, eff. 4-1-09; CR 15-041: cr. (3) (e), (f) Register December 2015 No. 720, eff. 1-1-16; CR 15-043: cr. (3) (d) 8. Register December 2015 No. 720, eff. 1-1-16.
SPS 321.25 SPS 321.25Wood frame walls. Unless designed through structural analysis, wood frame walls shall comply with the following requirements.
SPS 321.25(1) (1)Stud configuration. Wood studs shall comply with the size and spacing requirements indicated in Table 321.25-A. Studs in the exterior walls shall be placed with the wide faces perpendicular to the plane of the wall.
SPS 321.25 Note Note: See ch. SPS 325 Appendix A for acceptable nailing schedule.
SPS 321.25 Note Note: See s. SPS 321.10 for requirements on treating wood for decay and termite resistance.
SPS 321.25(2) (2)Top plates.
SPS 321.25(2)(a)(a) General. Except as allowed under subd. 3., top plates shall be provided and configured as follows:
SPS 321.25(2)(a)1. 1. Studs at bearing walls shall be capped with double top plates.
SPS 321.25(2)(a)2. 2. End joints in double top plates shall be offset at least 2 stud spaces.
SPS 321.25(2)(a)3. 3. Double top plates shall be overlapped at the corners and at intersections of partitions.
SPS 321.25(2)(a)4. 4. The plate immediately above the stud may have a joint only when directly over the stud.
SPS 321.25(2)(b) (b) Notching and boring.
SPS 321.25(2)(b)1.1. 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.
SPS 321.25 Note Note: 20 gauge is approximately 0.036 inch.
SPS 321.25(2)(b)2. 2. The steel angle shall span the gap and extend at least to the midpoint of the adjacent stud spaces.
SPS 321.25(2)(b)3. 3. Other equivalent materials may be used in accordance with s. SPS 321.02.
SPS 321.25(2)(c) (c) Exceptions.
SPS 321.25(2)(c)1.1. 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.
SPS 321.25(2)(c)2. 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.
SPS 321.25(2m) (2m)Bottom plates.
SPS 321.25(2m)(a)(a) Masonry foundation walls with open top course.
SPS 321.25(2m)(a)1.1. Where a masonry foundation wall has an open top course, a bottom plate at least as wide as the foundation wall shall be fastened to the foundation.
SPS 321.25(2m)(a)2. 2. Where anchor bolts are used on a masonry foundation wall with an open top course, the minimum width of an individual piece making up the bottom plate shall be at least 5 1/2 inches.
SPS 321.25 Note Note: A sill plate can be made of multiple pieces to achieve the full width.
SPS 321.25(2m)(b) (b) Extension beyond the bearing surface. All of the following requirements apply to a sawn-lumber sill plate with uniform loading that is partially extended beyond the load-bearing surface of a foundation wall in order to put the exterior surface of an upper-lying wall flush with or beyond the exterior surface of insulation which is placed on the outside of the foundation wall:
SPS 321.25(2m)(b)1. 1. The center of any anchor bolt shall be set back from the side edge of the sill plate by a distance of at least 4 times the diameter of the bolt.
SPS 321.25(2m)(b)2. 2. The thickness of the concrete or mortar cover around any anchor bolt shall comply with ACI 318 section 7.7.
SPS 321.25 Note Note: Under ACI 318 section 7.7, the minimum cover for a 5/8-inch-diameter or smaller bolt is 1 1/2 inches.
SPS 321.25(2m)(b)3. 3. Where a stud wall bears directly on a double bottom plate, the plate may not extend more than 1 1/2 inches beyond the load-bearing surface of the foundation wall.
SPS 321.25(2m)(b)4. 4. Where a stud wall bears directly on a single bottom plate, the plate may not extend more than 1 inch beyond the load-bearing surface of the foundation wall.
SPS 321.25(3) (3)Wall openings.
SPS 321.25(3)(am)(am) Headers. Where doors or windows occur, headers shall be used to carry the load across the opening.
SPS 321.25(3)(bm) (bm) Header size. The size of headers shall be determined in accordance with the spans and loading conditions listed in Tables 321.25-B, 321.25-C and 321.25-D. Headers for longer spans shall be designed by an engineering method under s. SPS 321.02.
SPS 321.25(3)(cm) (cm) Header support. Headers in bearing walls shall be supported in accordance with subd. 1. or 2. or 3.
SPS 321.25(3)(cm)1. 1. Headers 3 feet or less in length shall be directly supported on each end by either:
SPS 321.25(3)(cm)1.a. a. The single common stud and a shoulder stud; or
SPS 321.25(3)(cm)1.b. b. The single common stud with a framing anchor attached.
Published under s. 35.93, Stats. Updated on the first day of each month. Entire code is always current. The Register date on each page is the date the chapter was last published.