Wisconsin Legislature: 002 - CR 15-043 Rule Text

1The maximum length of the overhang is equal to one-fourth of the actual beam span length (0.25 x beam span).

Table 3A

MAXIMUM BEAM-SPAN LENGTH1 FOR DOUGLAS FIR/LARCH3, HEM/FIR3, SPRUCE/PINE/FIR (SPF)3, WESTERN CEDAR, PONDEROSA PINE4, AND RED PINE4

Joist Span

(Number of Plies) Beam Size2 – Inches

3x6

(2)2x6

3x8

(2)2x8

3x10

(2)2x10

3x12

(2)2x12

4x6

4x8

4x10

4x12

(3)2x6

(3)2x8

(3)2x10

(3)2x12

≤ 6'

5'-5"

6'-10"

8'-4"

9'-8"

6'-5"

8'-5"

9'-11"

11'-5"

7'-4"

9'-8"

12'-0"

13'-11"

≤ 8'

4'-8"

5'-11"

7'-3"

8'-5"

5'-6"

7'-3"

8'-7"

9'-11"

6'-8"

8'-6"

10'-5"

12'-1"

≤ 10'

4'-2"

5'-4"

6'-6"

7'-6"

4'-11"

6'-6"

7'-8"

8'-10"

6'-0"

7'-7"

9'-4"

10'-9"

≤ 12'

3'-10"

4'-10"

5'-11"

6'-10"

4'-6"

5'-11"

7'-0"

8'-1"

5'-6"

6'-11"

8'-6"

9'-10"

≤ 14'

3'-6"

4'-6"

5'-6"

6'-4"

4'-2"

5'-6"

6'-6"

7'-6"

5'-1"

6'-5"

7'-10"

9'-1"

≤ 16'

3'-1"

4'-1"

5'-1"

5'-11"

3'-11"

5'-2"

6'-1"

7'-0"

4'-9"

6'-0"

7'-4"

8'-6"

≤ 18'

2'-9"

3'-8"

4'-8"

5'-7"

3'-8"

4'-10"

5'-8"

6'-7"

4'-6"

5'-8"

6'-11"

8'-1"

1Spans are based on 40 psf live load, 10 psf dead load, normal loading duration, wet service conditions, and deflections of Δ=L/360 for main span and L/180 for overhang with a 220 lb. point load.

2Beam depth must be equal to or greater than joist depth if joist hangers are used (see Figure 8, Option 3).

3Incising is assumed.

4Design values based on northern species with no incising assumed.

Table 3B

MAXIMUM BEAM-SPAN LENGTH FOR SOUTHERN PINE1

Joist Span

(Number of Plies) Beam Size2 – Inches

(2) 2x6

(2) 2x8

(2) 2x10

(2) 2x12

(3) 2x6

(3) 2x8

(3) 2x10

(3) 2x12

≤ 6'

6'-11"

8'-9"

10'-4"

12'-2"

8'-2"

10'-10"

13'-0"

15'-3"

≤ 8'

5'-11"

7'-7"

9'-0"

10'-7"

7'-5"

9'-6"

11'-3"

13'-3"

≤ 10'

5'-4"

6'-9"

8'-0"

9'-5"

6'-8"

8'-6"

10'-0"

11'-10"

≤ 12'

4'-10"

6'-2"

7'-4"

8'-7"

6'-1"

7'-9"

9'-2"

10'-9"

≤ 14'

4'-6"

5'-9"

6'-9"

8'-0"

5'-8"

7'-2"

8'-6"

10'-0"

≤ 16'

4'-3"

5'-4"

6'-4"

7'-6"

5'-3"

6'-8"

7'-11"

9'-4"

≤ 18'

4'-0"

5'-0"

6'-0"

7'-0"

5'-0"

6'-4"

7'-6"

8'-10"

1Spans are based on 40 psf live load, 10 psf dead load, normal loading duration, wet service conditions, and deflections of Δ=L/360 for main span and L/180 for overhang with a 220 lb. point load.

2Beam depth must be equal to or greater than joist depth if joist hangers are used (see Figure 8, Option 3).

(See PDF for Figure)

Figure 4

BEAM ASSEMBLY

(See PDF for image)

SECTION 5: JOISTS

Joists must comply with all of the following:

The joist-span length is measured between the centerline of bearing at each joist-span end and does not include the overhangs. Use Table 4 to determine the joist size based on span length and joist spacing. See section 12.4 for limits on joist spacing if the decking consists of a wood-plastic composite.

See Figures 5 through 7 for joist-span types.

Joists must bear at least 3 inches nominal onto beams, unless joist hangers are used in accordance with section 7.

Joists may overhang past the center of the beam up to one-fourth of the actual joist span.

Provide full-depth 2x blocking or bridging for 2x10 or deeper joists at intervals not exceeding 8 feet – except the blocking can be reduced to 60% of the height if placed above a beam, for drainage purposes. Attach the blocking or bridging with (3)10d toe-nails at each end.

Attach a continuous rim joist as shown in Figures 5 and 7 unless blocking or bridging is provided for each joist at the beam where a joist overhang begins. Attach the rim joist to the end of each joist with (3)10d nails or (3)#10 by 3-inch wood screws.

(See PDF for Figure)

Figure 5

JOISTS WITH DROPPED BEAM – DECK ATTACHED AT HOUSE

(See PDF for image)(See PDF for image)

1The maximum length of the overhang is equal to one-fourth of the actual joist span length (0.25 x joist span).

(See PDF for Figure)

Figure 6

JOISTS WITH FLUSH BEAM – DECK ATTACHED AT HOUSE

(See PDF for Figure)

Figure 7

JOISTS WITH TWO DROPPED BEAMS/FREE-STANDING DECK

(See section 10 for more information.)

(See PDF for image)

1The maximum length of the overhang is equal to one-fourth of the actual joist span length (0.25 x joist span).

Table 4

MAXIMUM JOIST-SPAN LENGTH1

Joist Spacing

(on center)

Joist Size

Douglas Fir/Larch,

Hem/Fir, SPF2

Southern Pine

Without Overhang

With Overhangs

Without Overhang

With Overhangs

12"

2x6

9’-1”

8’-1”

9'-6"

8'-7"

12"

2x8

12'-6"

9'-5"

13'-1"

10'-1"

2x10

15'-8"

13'-7"

16'-2"

14'-6"

2x12

18'-0"

16"

2x6

8’-3”

8’-0”

8'-7"

2x8

11'-1"

9'-5"

11'-10"

10'-1"

2x10

13'-7"

14'-0"

2x12

15'-9"

16'-6"

24"

2x6

6’-9”

7'-6"

2x8

9'-1"

9'-8"

2x10

11'-1"

11'-5"

2x12

12'-10"

13'-6"

1Spans are based on 40 psf live load, 10 psf dead load, normal loading duration, wet service conditions and deflections of Δ=L/360 for main span and L/180 for overhang with a 220 lbs. point load.

2Incising is assumed.

SECTION 6: JOIST-TO-BEAM CONNECTIONS

Joists must be attached to beams in accordance with Figure 8 and all of the following:

Use Options 1 or 2 if joists bear on a dropped beam.

Use Option 3 if joists bear at a flush beam; see section 7 for hanger requirements.

Mechanical fasteners or hurricane clips must have a minimum capacity of 100 pounds in both uplift and lateral directions. Installation must be in accordance with the manufacturer's instructions.

(See PDF for Figure)

Figure 8

JOIST-TO-BEAM CONNECTIONS

1Option 1 is not allowed on free-standing decks.

SECTION 7: JOIST HANGERS

Joist hangers must comply with all of the following:

The joist-hanger depth (d, as shown in Figure 9) must be at least 60 percent of the joist depth.

The manufactured width of the joist hanger must accommodate the number of plies being carried.

Do not bend hanger flanges to accommodate field conditions.

For joist hangers that are fastened to a ledger board, screws which are recommended by the manufacturer must be used. All other fasteners are permitted to be nails. The number of fasteners and the manner in which they are used must be as specified by the manufacturer.

Use joist hangers with inside flanges if clearances to the edge of the beam or ledger board dictate.

Clip-angles or brackets used to support framing members in lieu of joist hangers are prohibited.

Joists must not frame in from both sides of the same beam. Engineering analysis is needed if more beams are needed than are shown in Figures 5 to 7.