Wisconsin Legislature: 002 - CR 15-043 Rule Text

MAXIMUM POST HEIGHT

Post Size

Maximum Height

4x4

4x6

6x6

14'

Any post supporting a beam splice must be a minimum of 6x6.

Beams must be attached to posts by the appropriate methods shown in Figure 2. Toe-nailing of beams to posts is prohibited.

Post caps, as shown in Figure 2, must be specifically designed for 2- or 3-ply beams and the post size used. Attachment must be in accordance with the manufacturer’s instructions.

It is recommended that cut-ends of posts should be field-treated with a wood preservative. These preservatives can be found in the paint department of most hardware or home-center stores.

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Figure 2

POST-TO-BEAM CONNECTIONS

SECTION 4: BEAMS

Beams must comply with all of the following:

As shown in Figure 3, the beam-span length is measured between the centerlines of two adjacent posts and does not include the overhangs.

Beam size is determined using Table 3A or 3B. The depth of flush beams must be greater than or equal to the joist depth.

Beams may overhang past the center of the post up to one-fourth of the actual beam span, as shown in Figure 3.

Where multiple 2x members are used to assemble a beam, the plies of the beam must be fastened in accordance with Figure 4.

Pressure-preservative-treated glulam beams are permissible for spans longer than those shown in Table 3. However, a design and plan submission is required during the permit application process.

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Figure 3

BEAM TYPES

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

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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.

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Figure 5

JOISTS WITH DROPPED BEAM – DECK ATTACHED AT HOUSE

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