SPS 321.20(3)
(3) When a concrete floor is placed on sand or gravel soils, the base course may be omitted unless drain tile is installed. If drain tile is installed, the requirements of s.
SPS 321.17 shall be met.
SPS 321.20 History
History: Cr.
Register, November, 1979, No. 287, eff. 6-1-80; am.
Register, January, 1989, No. 397, eff. 2-1-89; r. and recr.
Register, January, 1999, No. 517, eff. 2-1-99; correction in (3) made under s.
13.92 (4) (b) 7., Stats.,
Register December 2011 No. 672.
SPS 321.203(1)(1)
Materials. Garage floors shall be constructed of concrete or other noncombustible materials which are impermeable to petroleum products. Slab-on-grade concrete garage floors shall be at least 4 inches thick and placed over at least 4 inches of granular fill.
SPS 321.203 Note
Note: It is not the intent of sub. (1) to require a concrete floor to be sealed to make it completely impermeable.
SPS 321.203(2)
(2)
Configuration. The floor shall be sloped such that water is removed in accordance with one of the following:
SPS 321.203(2)(a)
(a) Water drains toward the overhead door or to exterior grade such that no damage will be caused to any structural member or wall covering of the garage or the dwelling.
SPS 321.203 Note
Note: See s.
SPS 382.34 for floor drain requirements.
SPS 321.203 History
History: Cr.
Register, November, 1995, No. 479, eff. 12-1-95;
CR 02-077: r. and recr. (2)
Register May 2003 No. 569, eff. 8-1-03; correction in (2) (b) made under s.
13.92 (4) (b) 7., Stats.,
Register December 2011 No. 672.
SPS 321.205
SPS 321.205 Wood floors in contact with the ground. Wood floors in contact with the ground shall comply with the requirements under s.
SPS 321.18 (4).
SPS 321.205 History
History: Cr.
Register, January, 1989, No. 397, eff. 2-1-89; am.
Register, January, 1999, No. 517, eff. 2-1-99; correction made under s. 13.93 (2m) (b) 7., Stats.,
Register, March, 2001, No. 543;
CR 02-077: r. and recr.
Register May 2003 No. 569, eff. 8-1-03; correction made under s. 13.92 (4) (b) 7., Stats.,
Register December 2011 No. 672.
SPS 321.21
SPS 321.21 Precast concrete floors. Precast concrete floors shall be designed through structural analysis, or load tables furnished by the precast product fabricator may be used, provided the load tables were developed using structural analysis or load testing.
SPS 321.21 History
History: Cr.
Register, November, 1979, No. 287, eff. 6-1-80; r. and recr.
Register, March, 1992, No. 435, eff. 4-1-92.
SPS 321.22
SPS 321.22 Wood frame floors. Unless designed through structural analysis, wood frame floors shall comply with the following requirements:
SPS 321.22(1)(a)2.
2. Where the joists of a floor system are parallel to, and located between bearing walls above and below, the joists shall be doubled.
SPS 321.22(1)(b)
(b)
Floor joists on concrete walls. Where a sill plate is provided for floor joists on poured concrete, the sill plates shall be fastened to the foundation.
SPS 321.22 Note
Note: Section
SPS 321.18 (1) (d) requires the floor joists to also be fastened to the sill plate.
SPS 321.22(1)(c)
(c)
Floor joists on masonry walls with a solid top course. Where a sill plate is provided for floor joists on solid block top course masonry, the sill plate shall be fastened to the foundation.
SPS 321.22(1)(d)1.
1. Where the masonry wall has an open top course, a sill plate at least as wide as the foundation wall shall be fastened to the foundation.
SPS 321.22(1)(d)2.
2. Where anchor bolts are used on masonry walls with an open top course, the minimum width of an individual piece making up the sill plate shall be at least 5.5 inches.
SPS 321.22 Note
Note: A sill plate can be made of multiple pieces to achieve the full width.
SPS 321.22(2)
(2)
Floor trusses. Metal plate connected wood floor trusses shall be designed in accordance with the Design Specifications for Metal Plate Connected Parallel Chord Wood Trusses and the National Design Specification for Wood Construction. Truss members shall not be cut, bored or notched.
SPS 321.22(3)(a)(a) Girders and beams shall be selected from Table 321.22-A1 or Table 321.22-A2 or shall be designed through structural analysis.
SPS 321.22(3)(b)
(b) Wood girders and beams shall be fitted at the post or column. Adjoining ends shall be fastened to each other to transfer horizontal loads across the joint. Beams shall also be fastened to the posts with framing anchors, angle clips, or equivalent.
SPS 321.22(3)(c)
(c) Where intermediate beams are used, they shall rest on top of the girders; or shall be supported by ledgers or blocks fastened to the sides of the girders; or they may be supported by approved metal hangers into which the ends of the beams shall be fitted.
SPS 321.22(3)(d)
(d) Lateral restraint for all wood beams shall be provided at all columns using a saddle or other approved connection where the beam meets one of the following conditions:
SPS 321.22 Note
Note: A saddle supports the beam on the bottom and allows for the through-connection of fasteners into the side of the beam.
SPS 321.22(4)(a)1.1. `Joists.' Wood joists made of sawn lumber shall meet the following bearing requirements:
SPS 321.22(4)(a)1.a.
a. Wood joists supported on wood or metal shall have a bearing surface of at least 1
½-inches measured from the end of the joist.
SPS 321.22(4)(a)1.b.
b. Wood joists supported on masonry or concrete shall have a bearing surface of at least 3 inches measured from the end of the joist.
SPS 321.22(4)(a)1.c.
c. The tail end of a floor joist may not extend past the edge of a beam by more than the depth of the floor joist.
SPS 321.22(4)(a)1.d.
d. Wood floor joists with ends that intersect over a beam shall have the ends overlap at least 3 inches and be securely fastened together with at least two 12d common nails or the ends shall be butt-jointed or face-jointed and fastened with ties, straps, plates or solid blocking.
SPS 321.22(4)(a)2.
2. `Beams and girders.' Beams and girders made of sawn lumber shall have a bearing surface on their supports of at least 3 inches parallel to the beam or girder and be at least as wide as the beam or girder.
SPS 321.22(4)(b)
(b) Engineered wood products. Bearing surface for engineered wood products shall be in accordance with the manufacturer's instructions provided those instructions were developed through structural analysis or product testing and are applicable to the configuration.
SPS 321.22(5)
(5)
Notching and boring. Notching and boring of beams or girders is prohibited unless determined through structural analysis.
SPS 321.22(5)(a)1.1. Notches located in the top or bottom of floor joists shall not have a depth exceeding
1
/6 the depth of the joist, shall not have a length exceeding
1/3 the joist depth nor be located in the middle
1/3 of the span of the joist.
SPS 321.22(5)(a)2.
2. Where floor joists are notched on the ends, the notch shall not exceed
¼ the depth of the joist. Notches over supports may extend the full bearing width of the support.
SPS 321.22(5)(b)1.1. `General.' A hole may not be bored in a floor joist within 2 inches of a notch or another hole. In no case shall the distance between adjacent holes be less than the diameter of the larger hole.
SPS 321.22(5)(b)2.
2. `Holes near the edge.' Holes bored in the top or bottom 2 inches of a joist shall follow the limitations for notching under par.
(a).
SPS 321.22(5)(b)3.
3. `Other holes.' Holes bored in floor joists that are not within 2 inches of the top or bottom of the joist shall have their diameter limited to
1/3 the depth of the joist.
SPS 321.22(5)(c)
(c) Engineered wood products. Notching or boring of engineered wood products shall be done in accordance with the manufacturer's instructions provided those instructions were developed through structural analysis or product testing.
SPS 321.22(6)(a)(a)
General. Except as provided in pars.
(b) and
(c), a floor joist overhang shall be cantilevered beyond the outer edge of the supporting wall below it by no more than the actual depth of the joist or shall be designed through structural analysis in accordance with s.
SPS 321.02 (3).
SPS 321.22(6)(b)
(b) Joist overhangs parallel to the main floor framing system. Joist overhangs that are extensions of, and parallel to, the main floor framing system may extend beyond the depth of the joist without structural analysis provided they meet all of the following conditions:
SPS 321.22(6)(b)1.
1. The overhang is cantilevered no more than 2 feet beyond the outer edge of the supporting wall below it.
SPS 321.22(6)(b)2.a.a. The overhang supports a uniform load limited to the weight of the bearing wall and the tributary roof area above it.
SPS 321.22(6)(b)2.b.
b. The tributary length of the roof area, excluding the eave overhang, is no more than 2 feet greater than the actual length of the joist directly below.
SPS 321.22 Note
Note: The tributary length is usually half the span of the joist or rafter.
SPS 321.22(6)(b)3.
3. The joist overhang does not support any concentrated loads. For the purposes of this subsection, a framed opening in the wall with a rough opening of 4 feet or less shall be considered uniform loading.
SPS 321.22(6)(b)4.b.
b. The doubled joist length extends inward beyond the inner edge of the supporting wall by the same distance as the cantilever.
SPS 321.22(6)(b)4.c.
c. The added joist member is secured to the main joist as stated in the nailing schedule in ch.
SPS 325 Appendix A, under the heading for “floor framing, built-up girder and beams, top loaded".
SPS 321.22(6)(c)
(c) Joist overhangs perpendicular to the main floor framing system. Joist overhangs that are perpendicular to the main floor framing system, or lookout joists, may extend beyond the depth of the joist without structural analysis provided they meet all of the following conditions:
SPS 321.22(6)(c)1.
1. The joist overhang is cantilevered no more than 2 feet beyond the outer edge of the supporting wall below it.
SPS 321.22(6)(c)2.b.
b. The double floor joist is located a distance of at least 2 times the cantilever length inward from the outer edge of the supporting wall below.
SPS 321.22(6)(c)3.
3. The joist overhang supports no more than either a non-bearing wall or a wall that supports only a roof which spans no more than the floor overhang cantilever length plus the eave overhang.
SPS 321.22(6)(d)
(d) All overhangs longer than the depth of the supporting joist that do not meet all of the conditions under par.
(b) or
(c) shall be designed through structural analysis.
SPS 321.22(7)
(7)
Floor openings. Trimmers and headers shall be doubled when the span of the header exceeds 4 feet. Headers which span more than 6 feet shall have the ends supported by joist hangers or framing anchors, unless the ends are supported on a partition or beam. Tail joists (joists which frame into headers) more than 8 feet long shall be supported on metal framing anchors or on ledger strips of at least 2 inches by 2 inches nominal.
1This table is based upon wood with a fiber bending stress of 1,000 psi. Two acceptable wood beam selections are listed for each loading condition.
2Two acceptable steel beam selections are listed for each loading condition. The first entry is the most economical selection based upon beam weight.
3Wood main beams or girders may be built up from nominal 2-inch members. The 2-inch members shall be laid on edge and fastened together with a double row of common nails not less than 3½-inches in length. Nails shall be spaced not more than 18 inches apart in each row with the end nails placed 4 inches to 6 inches from the end of each piece. Where built-up beams are employed over a single span, the length of each individual piece used to fabricate the beam shall equal the length of the beam.
- See PDF for table 
1This table provides maximum allowable spans in feet and inches for main beams or girders which are built-up from nominal 2-inch members.
2Fiber bending stress for various species and grades of wood is given in Appendix A321.
3The 2-inch members shall be laid on edge and fastened together with a double row of common nails not less than 3½-inches in length. Nails shall be spaced not more than 18 inches apart in each row with the end nails placed 4 inches to 6 inches from the end of each piece.
4Where built-up wood beams are employed over a single span, the length of each individual piece used to fabricate the beam shall equal the length of the beam.
5Where built-up wood beams are continued over more than one span and where lengths of individual pieces are less than the total length of the complete beam, butt joints shall be located over supports or within 6 inches of the quarter points of the clear span. Where located near the quarter points, the joints in built-up beams shall be separated by at least one lamination and shall not exceed the beam width.
SPS 321.22(8)(a)
(a) Plywood sheathing. Plywood sheathing used for floors shall be limited to the allowable loads and spans shown in Table 321.22-B.
