Wisconsin Administrative Code › Department of Safety and Professional Services › SPS 301-399 - Safety, Buildings, and Environment › SPS 320-325 - Uniform Dwelling Code › Chapter SPS 325 - Plumbing › Appendix B - UDC Appendix

Current through June 24, 2024
SECTION 1: GENERAL REQUIREMENTS
1. All lumber, including for decking, must be
					 pressure-preservative-treated and must be either douglas fir/larch,
					 hemlock/fir, spruce/pine/fir (SPF), or southern pine, of grade #2 or better -
					 unless a naturally durable species such as a western red cedar is used. Lumber
					 in contact with the ground must be rated as "ground-contact." The lumber must
					 be identified by the grade mark of, or certificate of inspection issued by, a
					 professional lumber-grading or inspection bureau or agency (
www.alsc.org
).
Note:
Not all treated lumber is rated for
					 ground contact. See Table C-1 in Appendix C for further information.
Click to
					 view image
2. Wood-plastic composites must bear a label indicating
					 their performance criteria and compliance with ASTM D7032.
Note:
Wood-plastic composites are materials
					 composed of wood fibers or powder that is bound with plastic and used typically
					 as decking and elements of a guard or handrail.
Note:
When using a wood-plastic composite,
					 exercise caution as some composite members do not have the same capabilities as
					 their equivalent wood sizes.
3. Nails must be threaded, which includes ring-shanked
					 (annular-grooved) and spiral-grooved.
Note:
A 1/8 inch pilot hole is recommended for
					 all toe-nailing locations.
4. All fasteners must be galvanized steel, stainless steel,
					 or approved for use with preservative-treated lumber.
5. Throughout this document, 1/2 inch-diameter bolts and
					 lag screws are specified for various connections. Edge distance and spacing
					 requirements are based on 1/2 inch-diameter fasteners. If larger (or smaller)
					 fasteners are specified, edge distance and spacing need to be adjusted.
6. Carriage-bolts may be substituted where through-bolts
					 are specified, if carriage-bolt washers are installed at the bolt head.
Note:
Carriage-bolt washers have square
					 holes.
7. Hardware, including joist hangers or post anchors, must
					 be galvanized steel with 1.85 ounces of zinc per square foot (G-185 coating),
					 or stainless steel. All fasteners that are used with any hardware must be the
					 same material as the hardware. All hardware must be installed in accordance
					 with any instructions from the manufacturer.
Note:
For galvanized steel, look for product
					 lines such as "Zmax," "Triple Zinc," or "Gold Coat."
Note:
Galvanized steel is not compatible with
					 stainless steel, which can result in rapid corrosion and structural
					 failure.
Note:
Hardware and fasteners that are beneath
					 a hot tub which uses salt-water disinfection should be stainless steel, grade
					 304 or 316.
8. Every deck must have an electrical outlet along the
					 perimeter of the deck and withi n 6.5 feet of the floor in accordance with NEC
					 Section 210.52(E)(3). See ch. SPS 316 of the Wisconsin Administrative Code for
					 requirements about installing electrical wiring.
9. A deck constructed in accordance with these standards is
					 not approved for concentrated loads that exceed 40 pounds per square foot
					 (psf), such as from privacy screens, planters, built-in seating, hot tubs,
					 stairs for multiple-level decks, or from snow-drift loads or sliding-snow
					 loads. Engineering analysis is needed for these loads.
Note:
See Appendix C for features of a deck
					 which are somewhat uncommon or which have more complexity than is addressed in
					 this Appendix - such as design values for joists consisting of western cedar or
					 red pine, framing details around chimneys and bay windows, or ledger boards for
					 metal-plate-connected wood floor trusses. Appendix C also includes reference
					 material, such as more-detailed specifications for fasteners.
10. Specifications for fasteners and hardware
.
All nails must meet the requirements of ASTM F1667. Wood screws must meet the
					 requirements of ANSI/ASME B18.6.1. Bolts and lag screws must meet the
					 requirements of ANSI/ ASME B18.2.1.
Fasteners to be hot-dipped galvanized must meet the
					 requirements of ASTM A153,
Standard Specification for Zinc Coating
					 (Hot-Dip) on Iron and Steel Hardware,
Class D for fasteners 3/8"
					 diameter and smaller or Class C for fasteners with diameters over 3/8".
Fasteners other than nails and timber rivets may consist of
					 mechanically deposited zinc-coated steel with coating weights in accordance
					 with ASTM B695, Class 55, minimum.
Hardware to be hot-dipped prior to fabrication must meet
					 ASTM A653
, Standard Specification for Steel Sheet, Zinc-Coated
					 (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip
					 Process
, G-185 coating. Hardware to be hot-dipped galvanized after
					 fabrication must meet ASTM A123
, Specification for Zinc (Hot-Dip
					 Galvanized) Coatings on Iron and Steel Products.
11. Safety glazing at decks shall be in accordance with the
					 safety glazing requirements of the Uniform Dwelling Code (UDC).
SECTION 2: FOOTINGS, AND POST CONNECTIONS
Footings must comply with all of the following:
1. Concrete must be used and must have a minimum
					 compressive strength of 3,000 pounds per square inch.
2. Footing size and thickness must be in accordance with
					 Table 1. (See sections 4 and 5 for determining post spacing and joist
					 length.)
3. Post attachments must be in accordance with Figure 1
					 except expansion anchors are also permitted - and any instructions from the
					 manufacturer of the anchor must be followed.
4. Post anchors must include a 1-inch-minimum base plate.
					 Steel plates are not required.
5. Each post must bear directly over the middle one-third
					 of a footing.
6. Footings must bear on solid ground below the frost
					 penetration level or at least 48 inches below finished grade, whichever is
					 deeper. Bearing onto unprepared fill material, organic soil, alluvial soil, or
					 mud is prohibited. The bearing capacity of the soil is presumed to be at least
					 2000 pounds per square foot (psf), and must be verified by a building inspector
					 prior to placement of concrete.
7. If the edge of a deck footing is closer than 5 feet to
					 an existing house wall, the footing must bear at the same elevation as the
					 existing footing for that wall.
8. Construction of footings over utility lines or any
					 service pipe is prohibited.
Note:
Call the utility provider before
					 digging.
Table 1 FOOTING SIZE (In
					 Inches)1,2,3
Joist Length
Post Spacing (Measured Center to
								  Center)
4'
5'
6'
7'
8'
9'
10'
11'
12'
13'
14'
6'
Corner Footing Intermediate Footing
8
10
9
11
10
12
11
13
11
14
12
15
12
15
13
16
14
17
14
17
15
18
Footing Thickness
6
6
6
6
6
6
6
6
6
6
8
7'
Corner Footing Intermediate Footing Footing
								  Thickness
9
11
10
12
11
13
11
14
12
15
13
16
13
17
14
17
15
18
15
19
16
19
6
6
6
6
6
6
6
6
8
8
8
8'
Corner Footing Intermediate Footing
10
12
10
13
11
14
12
15
13
16
14
17
14
18
15
19
15
19
16
20
17
21
Footing Thickness
6
6
6
6
6
6
8
8
8
8
8
9'
Corner Footing Intermediate Footing
10
12
11
14
12
15
13
16
14
17
14
18
15
19
16
20
16
20
17
21
18
22
Footing Thickness
6
6
6
6
6
8
8
8
8
8
8
10'
Corner Footing Intermediate Footing
10
13
12
14
12
15
13
17
14
18
15
19
16
20
16
21
17
21
18
22
18
23
Footing Thickness
6
6
6
6
8
8
8
8
8
8
10
11'
Corner Footing Intermediate Footing
11
13
12
15
13
16
14
17
15
19
16
20
16
21
17
22
18
22
19
23
19
24
Footing Thickness
6
6
6
6
8
8
8
8
8
10
10
12'
Corner Footing Intermediate Footing
11
14
12
15
14
17
15
18
15
19
16
20
17
21
18
22
19
23
19
24
20
25
Footing Thickness
6
6
6
8
8
8
8
8
10
10
10
13'
Corner Footing Intermediate Footing
12
14
13
16
14
17
15
19
16
20
17
21
18
22
19
23
19
24
20
25
21
26
Footing Thickness
6
6
6
8
8
8
8
10
10
10
10
14'
Corner Footing Intermediate Footing
12
15
13
17
15
18
16 19
17 21
18
22
18
23
19
24
20
25
21
26
22
27
Footing Thickness
6
6
8
8
8
8
10
10
10
10
10
15'
Corner Footing Intermediate Footing
12
15
14
17
15
19
16
20
17
21
18
23
19
24
20
25
21
26
22
27
22
28
Footing Thickness
6
6
8
8
8
10
10
10
10
10
12
16'
Corner Footing Intermediate Footing
13
16
14
18
15
19
17
21
18
22
19
23
20
25
20 26
21
27
22
28
23
29
Footing Thickness
6
8
8
8
8
10
10
10
10
12
12
1All footing sizes are base
					 diameters2.
2For square footings, insert the
					 diameter (d) into the following formula:
					 [RADIC]((d/2)2 x [PI] ). This number will give you
					 the square dimension and must be rounded up to the nearest inch.
3Joist length is the joist span
					 plus any overhang beyond a beam. See Section 5.4.
Click to
					 view image
SECTION 3: POSTS AND POST-TO-BEAM CONNECTIONS
Posts must comply with all of the following:
1. The post height, measured from the top of the footing to
					 the underside of the beam, must be in accordance with Table 2.
Table 2
MAXIMUM POST HEIGHT
Post Size
Maximum Height
4"x4"
6'
4"x6"
8'
6"x6"
14'
2. Any post supporting a beam splice must be a minimum of
					 6"x6".
3. Beams must be attached to posts by the appropriate
					 methods shown in Figure 2. Toe-nailing of beams to posts is prohibited.
4. 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.
5. 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.
Click to
					 view image
SECTION 4: BEAMS
Beams must comply with all of the following:
1. As shown in Figure 3, the beam-span length is measured
					 between the centerlines of 2 adjacent posts and does not include the
					 overhangs.
2. Beam size is determined using Table 3A or 3B. The depth
					 of flush beams must be greater than or equal to the joist depth.
3. Beams may overhang past the center of the post up to
					 one-fourth of the actual beam span, as shown in Figure 3.
4. Where multiple 2x members are used to assemble a beam,
					 the plies of the beam must be fastened in accordance with Figure 4.
5. 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.
Click to
					 view image
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 D =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
					 PINE
1
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 D =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).
Click to
					 view image
SECTION 5: JOISTS
Joists must comply with all of the following:
1. 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.
2. See Figures 5 through 7 for joist-span types.
3. Joists must bear at least 3 inches nominal onto beams,
					 unless joist hangers are used in accordance with section 7.
4. Joists may overhang past the center of the beam up to
					 one-fourth of the actual joist span.
5. Provide full-depth 2x blocking or bridging for 2"x10" 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.
6. 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.
Click to
					 view image
1The maximum length of the
					 overhang is equal to one-fourth of the actual joist span length (0.25 x joist
					 span).
Click to
					 view image
Click to
					 view 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
					 LENGTH
1
Joist Spacing (on center)
Joist Size
Douglas Fir/Larch, Hem/Fir,
								  SPF2
Southern Pine
Without Overhang
With Overhangs
Without Overhang
With Overhangs
12"
2"x6"
9'-1"
8'-1"
9'-6"
8'-7"
2"x8"
12'-6"
9'-5"
13'-1"
10'-1"
2"x10"
15'-8"
13'-7"
16'-2"
14'-6"
2"x12"
18'-0"
18'-0"
18'-0"
18'-0"
16"
2"x6"
8'-3"
8'-0"
8'-7"
8'-7"
2"x8"
11'-1"
9'-5"
11'-10"
10'-1"
2"x10"
13'-7"
13'-7"
14'-0"
14'-0"
2"x12"
15'-9"
15'-9"
16'-6"
16'-6"
24"
2"x6"
6'-9"
6'-9"
7'-6"
7'-6"
2"x8"
9'-1"
9'-1"
9'-8"
9'-8"
2"x10"
11'-1"
11'-1"
11'-5"
11'-5"
2"x12"
12'-10"
12'-10"
13'-6"
13'-6"
1Spans are based on 40 psf live
					 load, 10 psf dead load, normal loading duration, wet service conditions, and
					 deflections of D =L/360 for main span and L/180 for overhang with a 220 lb.
					 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:
1. Use Options 1 or 2 if joists bear on a dropped
					 beam.
2. Use Option 3 if joists bear at a flush beam; see section
					 7 for hanger requirements.
3. 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.
Click to
					 view image
1 Option 1 is not allowed on
					 free-standing decks.
SECTION 7: JOIST HANGERS
Joist hangers must comply with all of the following:
1. The joist-hanger depth (d, as shown in Figure 9) must be
					 at least 60 percent of the joist depth.
2. The manufactured width of the joist hanger must
					 accommodate the number of plies being carried.
3. Do not bend hanger flanges to accommodate field
					 conditions.
4. 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.
5. Use joist hangers with inside flanges if clearances to
					 the edge of the beam or ledger board dictate.
6. Clip-angles or brackets used to support framing members
					 in lieu of joist hangers are prohibited.
7. 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.
8. Each joist hanger must have the minimum capacity listed
					 in Table 5.
Click
					 to view image
Table 5 JOIST HANGER DOWNLOAD
Joist Size
Minimum Capacity, lbs
2"x6"
500
2"x8"
500
2"x10"
600
2"x12"
700
SECTION 8: LEDGER ATTACHMENTS
General requirements.
Ledger boards must be
					 attached to the existing house in accordance with all of the following and
					 section 9. Compliance is critical to ensure the safety and structural stability
					 of your deck.
1. The ledger-board depth must be greater than or equal to
					 the depth of the deck joists, but not less than a 2"x8".
2. The ledger board must be attached in accordance with one
					 of the conditions shown in Figures 11 through 13 - except if
					 metal-plate-connected wood floor trusses were used in the house, see the text
					 below for manufactured wood trusses.
3. The existing band board on the house must be capable of
					 supporting the deck. If this cannot be verified or if existing conditions
					 differ from the details here, then a free-standing deck or an engineered design
					 is required.
4. The top of the ledger board and the top of the deck
					 joists must be at the same elevation.
Wood I-joists.
Many homes are constructed with
					 wood I-joists, as shown in Figure 10. Rather than utilize a 2x band board,
					 these systems are often constructed with a minimum 1-inch-thick engineered wood
					 product (EWP) band board capable of supporting a deck. If a minimum 1-inch EWP
					 or 2x band board is not present, then a freestanding deck is required, as
					 addressed in section 10.
Click
					 to view image
Manufactured wood trusses.
A
					 metal-plate-connected wood truss (MPCWT) is an engineered, prefabricated
					 structural component that is designed for each specific application. MPCWT
					 systems that are used in residential floors are often installed with a 2"x4"
					 lumber "ribbon" board at the ends of the trusses to tie the ends of the trusses
					 together (see Detail 1 in Appendix C.). The ribbon board, by itself, is not
					 intended to support the deck ledger and deck. Installing a residential deck
					 where the floor for the house uses a MPCWT system must be in accordance with a
					 standard detail provided by the truss designer, a corresponding detail in
					 section 7 of Appendix C, or a full plan submission - unless the deck is
					 free-standing as addressed in section 10.
Siding and flashing.
Flashing must be
					 installed in accordance with all of the following:
1. The exterior finish, such as house siding, must be
					 removed in the area for the ledger board prior to the installation of the
					 ledger board.
2. Continuous flashing with a drip edge, as shown in Figure
					 11, is required at a ledger board that is attached to wood-framed construction.
					 Caulking is needed with the flashing at a threshold to prevent water intrusion
					 due to splash from the deck or due to melting snow and ice.
3. Flashing must be a corrosion-resistant metal having a
					 minimum nominal 0.019-inch thickness - such as galvanized steel coated with
					 1.85 ounces of zinc per square foot (G-185 coating), copper (attached using
					 copper nails only), or stainless steel - or must be a UV-resistant plastic
					 recommended by its manufacturer for this use. Do not use aluminum in direct
					 contact with lumber treated with preservatives that contain copper, such as
					 ACQ, copper azole, or ACZA.
Click
					 to view image
Click
					 to view image
Click
					 to view image
Prohibited ledger attachments.
Attaching a
					 ledger board to or through an exterior veneer such as brick or stone, or to or
					 through a masonry chimney, or to a house overhang - as shown below - are
					 prohibited. In such cases, the deck must be free-standing, as addressed in
					 section 10. Attaching a ledger board to a house overhang is allowed if
					 supported by engineering.
Click
					 to view image
SECTION 9: LEDGER-BOARD FASTENERS
General requirements.
Ledger board fasteners
					 must be installed in accordance with this section. Placement and spacing must
					 be in accordance with Figure 15 and Table 6. Only the fastener types listed
					 here are approved for use; lead anchors are prohibited. Adequacy of connections
					 may be verified by local inspectors.
Click
					 to view image
Table 6 LEDGER BOARD FASTENER SPACING, ON
					 CENTER1,2,3
Fastener
Band Board
Joist Span: less than or equal
								  to
6'
8'
10'
12'
14'
16'
18'
Lag screws
1" EWP
24"
18"
14"
12"
10"
9"
8"
1 1/8" EWP
28"
21"
16"
14"
12"
10"
9"
2x Lumber
30"
23"
18"
15"
13"
11"
10"
Through-Bolts
1" EWP
24"
18"
14"
12"
10"
9"
8"
1 1/8" EWP
28"
21"
16"
14"
12"
10"
9"
2x Lumber
36"
36"
34"
29"
24"
21"
19"
Through-Bolts with 1/2" stacked
								  wash-ers4,5
2x Lumber
36"
36"
29"
24"
21"
18"
16"
Adhesive anchors
______
32"
32"
32"
24"
24"
16"
16"
1These values are valid for deck
					 ledgers consisting of douglas fir/larch, hem/fir, or southern pine; and for
					 band boards consisting of douglas fir-larch, hem-fir, spruce-pine-fir, southern
					 pine, or engineered wood product (EWP).
2Where solid-sawn
					 pressure-preservative-treated deck ledgers are attached to engineered wood
					 products (minimum 1" thick wood structural panel band joist or structural
					 composite lumber including laminated veneer lumber), the ledger attachment must
					 be designed in accordance with accepted engineering practice. These tabulated
					 values are in accordance with that practice and are based on 300 lbs and 350
					 lbs for 1" and 1 1/8" EWP rim board, respectively.
3 The thickness of the sheathing
					 over the band board must not exceed 15/32".
4 The maximum gap between the
					 face of the ledger board and face of the wall sheathing is 1/2".
5 Wood structural panel
					 sheathing, gypsum board sheathing, or foam sheathing is permitted between the
					 ledger board and the band board. Stacked washers are permitted in combination
					 with wood structural panel sheathing, but are not permitted in combination with
					 gypsum board or foam sheathing. The maximum distance between the face of the
					 ledger board and the face of the band board is 1".
Through-bolts.
Through-bolts must have a
					 diameter of 1/2 inch. Pilot holes for through-bolts must be 17/32 to 9/16
					 inches in diameter. Through-bolts must be equipped with washers at the bolt
					 head and nut. Bolts should be tightened 6 to 12 months after construction due
					 to drying and wood shrinkage.
Expansion anchors.
Expansion or adhesive
					 anchors must be used for attaching a ledger board to a concrete or solid
					 masonry wall, as shown in Figure 12. The bolt or threaded rod of expansion
					 anchors must have a diameter of 1/2 inch, which in some cases may result in
					 needing a 5/8 inch-diameter anchor. Expansion anchors must be installed in
					 accordance with the manufacturer's instructions and must be equipped with
					 washers.
Adhesive anchors.
Approved adhesive anchors
					 with a 1/2 inch-diameter threaded rod must be used for attaching a ledger board
					 to hollow masonry, as shown in Figure 13. Examples of approved adhesive anchors
					 include the Epcon Acrylic 7 by ITW Ramset/Red Head, and the HY-20 by Hilti.
					 Adhesive anchors are also permitted with concrete or solid masonry
					 installations. Adhesive anchors must be installed in accordance with the
					 manufacturer's instructions and must be equipped with washers. Adhesive
					 cartridges should remain on the jobsite for inspector verification.
Lag screws.
The diameter, length, and shank of
					 lag screws must comply with Figure 16. Lag screws must be equipped with washers
					 and be installed in the following sequence:
1. Drill a 1/2 inch-diameter hole in the ledger board and a
					 5/16 inch-diameter pilot hole into the solid-connection material of the
					 existing house.
2. Insert the lag screw through the ledger board and into
					 the pilot hole by turning. Do not drive with a hammer. Use soap or a
					 wood-compatible lubricant if needed to facilitate tightening.
3. Tighten each lag screw snugly, but do not over-tighten
					 so as to cause wood damage.
Click
					 to view image
SECTION 10: FREE-STANDING
A deck that is free-standing does not utilize the exterior
					 wall of the existing house to support vertical loads. Instead, an additional
					 beam is provided at or offset from the existing house wall, as shown in Figure
					 17. If the edge of a deck footing is closer than 5 feet to an existing exterior
					 house wall, the footing must bear at the same elevation as the existing wall
					 footing as shown in Figure 17. For a house with a basement, a cylindrical
					 footing (caisson) is recommended to minimize required excavation at the
					 basement wall.
Click
					 to view image
SECTION 11: LATERAL SUPPORT
A deck that is more than 24 inches above grade must resist
					 lateral loads in accordance with the following:
Diagonal Bracing.
Provide diagonal bracing
					 both parallel and perpendicular to the beam at each post as shown in Figure 18.
					 Where parallel to the beam, the bracing must be bolted to the post at one end
					 and to the beam at the other. Where perpendicular to the beam, the bracing must
					 be bolted to the post at one end and to a joist or blocking between joists at
					 the other. Where a joist does not align with the bracing location, provide
					 blocking between the adjacent joists.
Exceptions:
Bracing is not required
					 perpendicular to the house for a deck that is attached to the house with both a
					 ledger board under sections 8 and 9 and the connection specified in either
					 Figure 19 or 20. For a free-standing deck that is attached to the house as
					 specified in Figure 21, bracing parallel to the house may be omitted at the
					 beam adjacent to the house. All bracing may be omitted for a deck which is
					 attached to the house in accordance with sections 8 and 9 or Figure 21 and
					 which has all of its decking installed at a 45 degree angle to the deck
					 joists.
Click
					 to view image
Click
					 to view image
Tension-tie requirements.
Tension ties, if
					 used instead of perpendicular bracing as described above, must comply with all
					 of the following, but are not permitted for free-standing decks:
1. The deck joists and floor joists must be
					 parallel.
2. At least 4 ties must be installed, at the end joist and
					 first inside joist at each end of the deck as shown in Figure 19. A set of
					 tension-ties must be installed for each structurally independent section of a
					 multi-level deck.
3. Approved tension-ties include the LTS19-TZ from USP or
					 DTT1Z from Simpson Strong-Tie.
4. The minimum capacity of each tension-tie is 750
					 pounds.
5. Tension ties which are not available in a G-185 zinc
					 coating require a barrier membrane separating the tension tie and the
					 preservative-treated joist. The barrier membrane must be recommended for this
					 location by its manufacturer.
6. Tension-ties must be attached to the underside of the
					 joists in accordance with the manufacturer's instructions. Tension-ties must be
					 attached to the exterior wall with lag screws as shown in Figure 19. Lag screws
					 must penetrate a minimum of 3 inches into the sill plate or top plate of a
					 wood-framed wall.
7. Where attaching to a concrete wall, lags screws may be
					 replaced with adhesive or expansion anchors and a 1/2 inch threaded rod, with a
					 withdrawal capacity of at least 750 pounds. The anchor must be installed in
					 accordance with the manufacturer's instructions.
Click
					 to view image
Hold-down tension devices.
Hold-down tension
					 devices, if used instead of perpendicular bracing as described above, must be
					 provided in at least 2 locations per deck, and each device must have an
					 allowable-stress-design capacity of at least 1,500 pounds.
Free-standing deck - attachment to house.
Attach the deck's rim joist to the existing house exterior wall as shown in
					 Figure 21 for a free-standing deck, if diagonal bracing parallel to the house
					 is omitted, as described above. The wall must be sheathed with minimum 3/8 inch
					 wood structural panel sheathing. Use lag screws or through-bolts if fastening
					 to an existing band joist or wall stud; and use expansion or adhesive anchors
					 if fastening to concrete or masonry. Do not attach to brick veneers. Verify
					 this condition in the field prior to utilizing this method. Fasteners must be
					 16 inches on center and staggered in 2 rows. Flashing over the rim joist is
					 required and must be installed in accordance with the flashing provisions in
					 section 8.
Click
					 to view image
SECTION 12: DECKING
All decking materials must be wood or a wood-plastic
					 composite and must comply with all of the following:
1. Wood decking must be 2x4s, 2x6s, or five-quarter
					 span-rated decking boards. Wood-plastic-composite sizes must be in accordance
					 with the manufacturer's instructions. Plastic decking may be used if it is
					 approved by a professional testing organization for supporting a live load of
					 40 psf and is installed according to the manufacturer's instructions.
2. Decking must be attached in accordance with Figure 22,
					 and may be placed at an angle of 45 to 90 degrees to the joists unless
					 disallowed in the manufacturer's instructions. If the decking is wet, place it
					 with no gap so that after drying, a ?-inch gap is created.
3. Decking may overhang a joist by up to 3 inches unless
					 disallowed in the manufacturer's instructions.
4. The center-to-center joist spacing may be up to 24
					 inches for wood decking, but may not exceed 16 inches for
					 wood-plastic-composite decking unless specified otherwise by the
					 manufacturer.
5. Each wood decking member must bear on a minimum of 4
					 joists or intermediate blocking between joists.
6. Placement and attachment of wood-plastic composites must
					 be in accordance with the manufacturer's instructions.
7. Attach the decking to the rim joist in accordance with
					 Figure 23.
Click
					 to view image
Click
					 to view image
SECTION 13: GUARD AND POSTS
All open sides of a deck area that is more than 24 inches
					 above grade - at any point within 36 inches beyond the edge of the deck - must
					 have a guard that complies with Figure 24 and with all of the following:
1. Required horizontal guards shall not have openings from
					 the walking surface to the required guard height which allow passage of a
					 sphere 4 inches in diameter, when applying a force of 4 pounds.
2. Required guards at stairs shall not have openings which
					 allow passage of a sphere 4 3/8 inches in diameter, when applying a force of 4
					 pounds, other than the triangular opening at the side of an open stair formed
					 by the riser, tread, and bottom rail of a guard, which shall not allow passage
					 of a 6 inch sphere, when applying a force of 4 pounds.
3. Wet lumber must be spaced such that when shrinkage due
					 to drying occurs, a compliant opening is maintained.
4. Rope, cable, or a similar non-rigid material may be used
					 instead of balusters if it is strung with maximum openings of 3 1/2 inches and
					 with vertical supports no more than 4 feet apart.
5. The guard and posts must withstand a 200-pound load
					 applied in any direction.
6. Guard-infill components, such as balusters and panel
					 fillers, must withstand a horizontally applied, perpendicular load of 50 pounds
					 on any one-foot-square area.
7. Wood-plastic composites of equivalent dimensions may be
					 substituted for the guard cap and infill elements shown in Figure 24 if the
					 manufacturer's instructions permit this use.
Click
					 to view image
Guard posts.
Guard posts must be attached to
					 the deck structure in accordance with all of the following: Notching guard
					 posts, as shown in Figure 25, is prohibited.
1. Notching guard posts, as shown in Figure 25, is
					 prohibited.
2. Hold-down anchors must have a minimum capacity of 1,800
					 pounds.
3. Guard posts may be attached to either side of the end
					 joist or rim joist.
4. Bolt holes for a post must be at least 2 inches from the
					 wood edge, at least 2½ inches apart, and no more than 5 inches
					 apart.
5. Hold-down anchors, as shown in Figures 26 and 27, must
					 be used to attach the guard post to the end joist and rim joist,
					 respectively.
Click
					 to view image
Click
					 to view image
Click
					 to view image
SECTION 14: STAIRS
Stair dimensions.
Stair dimensions must comply
					 with all of the following:
1. The minimum width of a stairway is 36 inches.
2. Handrails and associated trim may project a maximum of 4
					 1/2 inches into the required width at each side of the stairway. The minimum
					 clear width at and below the handrail, including at treads and landings, cannot
					 be less than 31 1/2 inches where a handrail is installed on one side, and 27
					 inches where handrails are provided on both sides.
3. Stair geometry and openings must be as shown
Click
					 to view image
4. Within a stairway flight, the largest tread depth may
					 not exceed the smallest tread depth by more than 3/8 inch, and the largest
					 riser height may not exceed the smallest riser height by more than 3/8
					 inch.
5. If the total vertical height of a stairway exceeds 12
					 feet, an intermediate landing is required and must be constructed as a
					 free-standing deck with flush beams and with posts.
6. Any landing width must equal or exceed the total width
					 of the stairway it serves.
Stair stringers.
Stringers must comply with
					 all of the following:
1. Stringers must be sawn or solid 2"x12"s complying with
					 the above tread and riser dimensions.
2. Cut stringers must be spaced no more than 18 inches on
					 center.
3. Stringers must bear on a solid surface, a minimum of 3
					 1/2 inches thick and 8 inches in diameter, and attach to the deck or a landing
					 in accordance with Figure 28. Prior to placement of solid surface, all loose or
					 organic material shall be removed.
4. Stringer-span length is measured using the horizontally
					 projected distance between the centerlines of bearing at each end.
5. The span length of a cut stringer must not exceed 6
					 feet-0 inches, and the throat size of cut stringers must not be less than 5
					 inches, as shown in Figure 29.
Solid-stringer exception:
Stringers for a
					 stairway that has a width of 36 inches may have a horizontally projected span
					 of up to 13 feet 3 inches if the stairway is framed solely with 2 solid
					 stringers.
Intermediate-supported stringers:
If the total
					 stringer length exceeds the above dimensions, a 4"x4" post may be provided to
					 support the stringer and shorten its span length. The 4"x4" post must be
					 notched and bolted to the stringer in accordance with Figure 2. The post must
					 bear over the middle one-third of a footing that is constructed in accordance
					 with Figure 29 and must be attached as shown in Figure 2. An intermediate
					 landing as described above may also be provided to shorten the stringer
					 span.
Click
					 to view image
Click
					 to view image
Click
					 to view image
Click
					 to view image
Click
					 to view image
Tread and riser material.
Treads and risers
					 must comply with all of the following:
1. Tread material must be equivalent to the decking
					 specified in section 12 and be attached in accordance with Figure 31, except
					 wood-plastic composites must be attached in accordance with the manufacturer's
					 instructions.
2. Stairs constructed using the solid-stringer exception
					 noted above must have treads constructed of 2x wood material only and be
					 attached in accordance with Figure 30.
3. Risers that are not open (as shown in Figure 27) must be
					 framed with 1x lumber minimum or an manufacturer recommended wood-plastic
					 composite.
Click
					 to view image
Table 7 MINIMUM TREAD
					 SIZES1
Species
Cut Stringer
Solid Stringer
Douglas Fir/ Larch, Hem/ Fir,
								  SPF2
2x4 or 5/4
2x8 or 3x4
Southern Pine
2x4 or 5/4
2x8
Redwood, Western Cedars, Pon-derosa
								  Pine3, Red
Pine3
2x4 or 5/4
2x10 or 3x4
1
Assumes 300 lb
					 concentrated load, L/288 deflection limit, No. 2 grade, and wet service
					 conditions.
2
Incising assumed
					 for refractory species including Douglas fir-larch, hem-fir, and
					 spruce-pine-fir.
3
Design values
					 based on northern species with no incising assumed.
Stair guards.
Guards must be provided on all
					 open sides of stairs consisting of more than 3 risers. Stair guards must comply
					 with section 13 and Figure 32.
Click
					 to view image
Stair handrails.
A flight of stairs with more
					 than 3 risers must have at least one handrail that complies with all of the
					 following:
1. The handrail must be located at least 30 inches, but no
					 more than 38 inches above the nosing of the treads - except that a volute,
					 turnout, starting easing, or transition fitting may depart from these
					 dimensions. Measurement must be taken from the nosing to the top of the
					 rail.
2. The handrail must be attached to a stair guard or
					 exterior wall acting as a barrier as shown in Figure 33.
3. The handrail and connecting hardware must be decay- and
					 corrosion-resistant.
4. The handrail must have a smooth surface with no sharp
					 corners and must be graspable, as shown in Figure 34. Recessed sections may be
					 shaped from a 2"x6" or five-quarter board, as shown there.
5. Handrails must run continuously from a point directly
					 over the lowest riser to a point directly over the highest riser.
6. Handrails may be interrupted by guard posts.
Click
					 to view image
Click
					 to view image
Spiral stairs.
Stair dimensions above are for
					 standard stairs secured in accordance with methods shown in this appendix.
					 Spiral stairs are allowed at decks when designed in accordance with the
					 provisions of Chapter SPS 321.04. Connection of spiral stairs to decks and the
					 supporting load path shall be designed in accordance with accepted engineering
					 practices and with applicable provisions of the Uniform Dwelling Code.
SECTION 15: FRAMING PLAN
A typical framing plan shows a bird's-eye or plan view of
					 the joist and beam layout; the location of the ledger board, diagonal bracing
					 or hold-down devices, posts, and footings; and the type, size, and spacing of
					 the ledger board fasteners. You can use the sample typical deck framing plan
					 shown on the next page in combination with the requirements in this document to
					 complete your deck.
Click
					 to view image