SPS 327.31(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 327.31(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 327.31(5)
(5) Notching and boring. Notching and boring of beams or girders is prohibited unless determined through structural analysis.
SPS 327.31(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 327.31(5)(a)2.
2. Where floor joists are notched on the ends, the notch shall not exceed 1/4 the depth of the joist. Notches over supports may extend the full bearing width of the support.
SPS 327.31(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 327.31(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 327.31(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 327.31(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 327.31(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 327.20 (3).
SPS 327.31(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 327.31(6)(b)1.
1. The overhang is cantilevered no more than 2 feet beyond the outer edge of the supporting wall below it.
SPS 327.31(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 327.31(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 327.31 Note
Note: The tributary length is usually half the span of the joist or rafter.
SPS 327.31(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 327.31(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 327.31(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 327.31(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 327.31(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 327.31(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 327.31(6)(d)
(d)
Other joist overhangs. 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 327.31(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. Joists more than 8 feet long that frame into headers shall be supported on metal framing anchors or on ledger strips of at least 2 inches by 2 inches nominal.
SPS 327.31(8)(a)(a)
Plywood sheathing. Plywood sheathing used for floors shall be limited to the allowable loads and spans shown in Table 327.31-A.
SPS 327.31(8)(b)
(b)
Combination subfloor-underlayment. Combination subfloor-underlayment shall be installed in accordance with Table 327.31-B.
SPS 327.31(8)(c)
(c)
Floor boards. Where wood boards are used for floor sheathing, the boards shall comply with the minimum thicknesses shown in Table 327.31-C.
SPS 327.31(8)(d)
(d)
Planks. Planks shall be tongue and groove or splined and at least 2 inches, nominal, in thickness. Planks shall terminate over beams unless the joints are end matched. The planks shall be laid so that no continuous line of joints will occur except at points of support. Planks shall be nailed to each beam.
SPS 327.31(9)(a)(a)
Sawn lumber. Bridging shall be provided for sawn lumber framing at intervals not exceeding 8 feet where the nominal depth to thickness ratio is greater than 4 to 1.
SPS 327.31 Note
Note: This 4:1 ratio means bridging is required for wood-framed floors having nominal 2X10 or deeper solid-sawn-lumber joists, to provide restraint against rotation or lateral displacement.
SPS 327.31(9)(b)
(b)
Engineered products. Bridging shall be provided for engineered framing products in accordance with the manufacturer's recommendations.
SPS 327.31(10)
(10) Sill plates. 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 that is placed on the outside of the foundation wall:
SPS 327.31(10)(a)
(a) 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 327.31(10)(b)
(b) The thickness of the concrete or mortar cover around any anchor bolt shall comply with ACI 318 section 7.7.
SPS 327.31 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 327.31(10)(c)
(c) With wood floor joists that are parallel to the foundation wall, the sill plate may not extend beyond the load-bearing surface of the wall by more than one-half of the nominal thickness of the joist that bears on the sill plate.
SPS 327.31(10)(d)
(d) As used throughout this subchapter and in the standards that the subchapter incorporates by reference, the shorter side of the cross-sectional area of a wood member is the thickness of the member. The longer side of the cross-sectional area is the depth, when the longer side is vertical; and it is the width when the longer side is horizontal.
SPS 327.31 Note
Note: Under sub. (6), wood floor joists that are perpendicular to the foundation wall can extend beyond the foundation wall by a distance of up to the depth of the joist.
Table 327.31-A
ALLOWABLE SPANS FOR PLYWOOD FLOOR SHEATHING CONTINUOUS OVER TWO OR
MORE SPANS AND FACE GRAIN PERPENDICULAR TO SUPPORTS1
Span Rating2 Plywood Thickness Maximum span3
32/16 15/32”, 1/2”, 5/8” 16”5
40/20 19/32”, 5/8”, 3/4”, 7/8” 20”
4,5
48/24 23/32”, 3/4”, 7/8” 24”
1 These values apply to C-D, C-C, and Structural I and II grades only. Spans shall be limited to values shown because of possible effect of concentrated loads.
2 Span Rating appears on all panels in the construction grades listed in footnote 1.
3 Plywood edges shall have approved tongue and groove joints or shall be supported with blocking, unless 1/4 inch minimum thickness underlayment or 1 1/2 inches of approved cellular or lightweight concrete is installed or finished floor is 25/32-inch wood strip. Allowable uniform load based on deflection of 1/360 of span is 165 pounds per square foot.
4 For joists spaced 24 inches on center, plywood sheathing with Span Rating 40/20 or greater can be used for subfloors when supporting 1 1/2 inches lightweight concrete.
5 May be 24 inches if 25/32-inch wood strip flooring is installed at right angles to joists.
Table 327.31-B
MINIMUM THICKNESS FOR PLYWOOD COMBINATION
SUBFLOOR-UNDERLAYMENT. PLYWOOD CONTINUOUS OVER TWO OR MORE
SPANS AND FACE GRAIN PERPENDICULAR TO SUPPORTS1,2
Maximum Support Spacing3
16” o.c 20” o.c 24” o.c
Plywood Panel Panel Panel
Species Thickness Thickness Thickness
Plywood Grade Group (inches) (inches) (inches)
Sanded exterior type 1 1/2 5/8 3/4
2 & 3 5/8 3/4 7/8
4 3/4 7/8 1
Underlayment C-C All Groups APA Rated Sheathing and APA Rated
Plugged Sturd-I-Floor4 Sturd-I-Floor shall be installed consistent
with their rating.
1 Spans shall be limited to values shown, based on possible effect of concentrated loads.
2 Unsupported edges shall be tongue and groove or blocked except where 1/4 inch underlayment or 25/32-inch finish floor is used.
3 Underlayment, C-C Plugged, sanded exterior type: allowable uniform load based on deflection of L/360 span for spans 24 inches or less is 125 psf; and for spans 48 inches, 65 psf.
4 The department will accept subfloor underlayment panels such as Sturd-I-Floor which meet the requirements of APA manufacturing specifications for Sturd-I-Floor panels.
Table 327.31-C
MINIMUM THICKNESS OF FLOOR BOARDS
Minimum Net Thickness
Joist Spacing Perpendicular to Joist Diagonal to Joist
24” 11/16” 3/4”
16” 5/8” 5/8”
SPS 327.31 History
History: EmR1703: emerg. cr., eff. 2-6-17;
CR 17-017: cr.
Register March 2018 No. 747, eff. 4-1-18; (6) (d) (title) created under s.
13.92 (4) (b) 1., Stats.,
Register March 2018 No. 747.
SPS 327.32
SPS 327.32 Decks. A deck attached to a camping unit or any detached deck that serves an exit from a camping unit that meets the following requirements is in compliance with this code:
SPS 327.32(1)
(1) A deck shall be constructed to support the actual dead load and a minimum live load of 40 pounds per square inch acting on it without exceeding the allowable stresses of the material.
SPS 327.32(2)
(2) A deck attached to a camping unit shall have a ledger attachment that meets the requirement under
sub. (1).
SPS 327.32(3)
(3) Corrosion-resistant flashing shall be installed where a deck attaches to the wall or floor assembly of a camping unit.
