STATE OF WISCONSIN
Department of Safety and Professional Services
IN THE MATTER OF RULEMAKING PROCEEDINGS BEFORE THE
DEPARTMENT OF SAFETY AND
PROFESSIONAL SERVICES
PROPOSED ORDER OF THE
DEPARTMENT OF SAFETY AND
PROFESSIONAL SERVICES
ADOPTING RULES
(CLEARINGHOUSE RULE )
PROPOSED ORDER
An order of the
Department of Safety and Professional Services
to
renumber
Chapters
SPS
3
20
– 325 Appendix;
to renumber and amend
SPS
3
21.225 (intro.) and (1) to (6), and
324.01
;
to amend SPS 320.04 (6) (d) (Note), 320.09 (1) (Note) [1
7
]
and
(9) (c) (Note), 320.19 (1) (b) (Note)
and
(2) (c) (Note), 321.02 (1) (d) (Note)
and
(3) (b) 2., 321.03 (1) (e) (Note), 321.04 (3) (b) 5. c. (Note), 321.125 (3) (c) (Note)
and
(6) (b) (Note), 321.16 (2) (c) 3. (Note), 321.17 (3) (e) (Note) [2], 321.18 (1) (d) c., 321.22 (1) (a) (Note)
,
(3) (a) Table 321.22-A2 (Footnote) [2]
and
(6) (b) 3. c., 321.25 (1) (Note) [1], 321.25 Figure 321.25-A
,
(8) (d) 1.
and
(8) (d) 2., 321.27 (1) (b)
,
(2) (Note)
and
(5) (b) (Note), and 321.40 (1) (h) (Note);
and to create
SPS 321.225 (
2
)
, 321.24
(
3
)
(d) 8. and (Note),
324.01 (2)
and (Note), and Chapters
3
20
to
325
Appendix
B
, relating to one- and two-family dwellings
.
Analysis prepared by the Department of
Safety and Professional Services
.
------------------------------------------------------------------------------------------------------------
ANALYSIS
Statutes interpreted:
Statutory authority:
Explanation of agency authority:
Section
227.11 (2) (a)
of the Statutes authorizes the Department to promulgate rules interpreting any statute that is enforced or administered by the Department, if the rule is considered necessary to effectuate the purpose of the statute.
Sections
101.63 (intro.)
and
(1) (intro.)
require the Department to adopt rules which establish standards for the construction and inspection of one- and two-family dwellings and components thereof. No set of rules may be adopted that has not taken into account the costs of specific code provisions to home buyers in relationship to the benefits derived from the provisions.
Related statute or rule:
Various other statutes and rules promulgated by the Department address construction and inspection of
dwellings,
public buildings and places of employment.
Plain language analysis:
These rules
provide prescriptive deck standards which explain
,
in
laymens
terms, how to build an outdoor deck for one- and two-family dwellings.
The bulk of these rules will form an appendix to the Uniform Dwelling Code (UDC). T
hese standards
do
not
impose new restrictions
beyond
the
current
U
DC
requirements
and
do not preclude the use of
different
deck
materials and methods than those prescribed in these rules, as long as the deck meets the provisions of the UDC
.
Summary of, and comparison with, existing or proposed federal regulation:
An Internet-based search of the
Code of Federal Regulations
(CFR) and the
Federal Register
did not find any federal regulations relating to the rule revisions herein for
outdoor decks for
one- and two-family dwellings
.
Comparison with rules in adjacent states:
Illinois
:
An Internet-based search did not reveal the existence of a statewide one- and two-family dwelling code. Dwelling regulation appears to be left up to the individual local units of government.
Iowa
:
An
i
nternet
based search revealed
that the Iowa Building Code adopts the 2009 International Residential Code
(IRC)
. The Iowa Building Code applies statewide to state owned and funded buildings. The
2009 IRC does not include prescriptive deck standards
.
Michigan
:
An Internet-based search revealed a mandatory, statewide one- and two-family dwelling code. The Residential Construction Code under the Construction Code Commission’s General Rules, in section 408.305, contains the state amendments to the 2009 International Residential Code
.
The 2009 IRC does not include prescriptive deck standards.
Minnesota:
An Internet-based sea
rc
h revealed a mandatory, statewide one- and two-family dwelling code. The Minnesota Department of Labor and Industry, in Chapter 1309, adopts the 2006 IRC, chapters 2-10 and 43. Chapters
2
-
10
contain the general construction provisions of the IRC
. The st
a
te code is being revised effective June 1, 2015 and will ado
p
t the 2015 Minnesota version of the I
RC
developed by the International Code Council with input from Minnesota.
The 2015 IRC includes prescriptive deck standards similar to the standards in these rules.
Summary of factual data and analytical methodologies:
The Department received input during
numerous
meetings with the Dwelling Code Council. The makeup of this Council is established under section
15.407 (10)
of the Statutes and consists of members who are appointed by the Governor. The Council includes representatives of several types of small businesses.
The Council created a Deck Subcommittee to study and develop the prescriptive deck standards.
Through th
e Deck Subcommittee and the
Dwelling Code
Council, the Department was able to gather information on the potential impacts of the rule revisions contained herein.
Analysis and supporting documents used to determine effect on small business or in preparation of economic impact
analysis
:
The rule revisions are not expected to significantly impact small business because they would clarify and simplify current requirements rather than impose new restrictions.
Fiscal Estimate and Economic Impact Analysis:
The Fiscal Estimate and Economic Impact Analysis
are
attached.
Effect on small business
:
These proposed rules
are
not
expected to
have
an economic impact on small businesses, as defined in s.
227.114 (1)
, Stats. The Department’s Regulatory Review Coordinator may be contacted by email at
Eric.Esser@wisconsin.gov
, or by calling (608) 267-2435
.
Agency contact person
:
Dan Smith
,
Rules Coordinator
, Department of
Safety and Professional Services
, Division of
Policy Development
, 1400 East Washington Avenue, Room 151, P.O. Box 8935, Madison, Wisconsin 53708; telephone 608-
261-4463
; email at
Daniel2.Smith
@wisconsin.gov
.
Place where comments are to be submitted and deadline for submission
:
Comments may be submitted to
Dan Smith, Rules Coordinator
, Department of
Safety and Professional Services
, Division of
Policy Development
, 1400 East Washington Avenue, Room 151,
P.O. Box
8366
, Madison, WI 53708-8935, or by email to
Daniel2.Smith
@wisco
ns
in.gov
. Comments must be received on or before
*
to be included in the record of rule-making proceedings.
------------------------------------------------------------------------------------------------------------
TEXT OF RULE
SECTION 1.
SPS 320.04 (6) (d) (Note), 320.09 (1) (Note) [1] and (9) (c) (Note), 320.19 (1) (b) (Note) and (2) (c) (Note), 321.02 (1) (d) (Note) and (3) (b) 2., 321.03 (1) (e) (Note), 321.04 (3) (b) 5. c. (Note), 321.125 (3) (c) (Note) and (6) (b) (Note), 321.16 (2) (c) 3. (Note), 321.17 (3) (e) (Note) [2], 321.18 (1) (d) c., 321.22 (1) (a) (Note), (3) (a) Table 321.22-A2 (Footnote) [2] and (6) (b) 3. c., 321.25 (1) (Note) [1], 321.25 Figure 321.25-A, (8) (d) 1. and (8) (d) 2., 321.27 (1) (b), (2) (Note) and (5) (b) (Note), and 321.40 (1) (h) (Note)
are amended to read:
NOTE TO LRB:
CHANGE THE WORD “appendix” TO “ch.
SPS 325 Appendix A
” AT ALL OF THE LOCATIONS
LISTED ABOVE
SECTION 2.
SPS 320.07 (12m) is created to read:
SECTION 3.
SPS
3
21.225
is renumbered SPS 321.225 (1)
,
and (1) (intro.) and (a) to (e)
as renumbered
are amended to read:
SPS 321
.225
Decks
.
(1)
Decks attached to dwellings and
any
detached
decks
which
deck that
serves
an exit shall comply with
the applicable provisions of
this chapter
subchs.
II
to
X
of ch. SPS 321
, including
but not limited to
all of the following
:
(a)
Excavation requirements
of
under
s.
SPS 321.14
;
.
(c)
Frost penetration requirements
of
under
s.
SPS 321.16
;
.
(e)
Stair, handrail
,
and
guardrail
guard
requirements of s.
SPS 321.04
; and
.
SECTION 4.
SPS 321.225 (
2
)
is created to read:
SPS 321.225 (2)
A deck that complies with the standards in
Appendix B, and Appendix C if applicable,
shall be considered as complying with sub. (1).
SECTION 5.
SPS 321.24
(
3
)
(d) 8. and (Note)
are
created to read:
SPS 321.24 (3)
(d) 8.
Along the bottom of door openings that are elevated above-grade.
Note:
Flashing placed along the bottom of a door
opening
that is elevated above-grade can subsequently accommodate add
ing
a
deck
outside
the door.
SECTION 6.
SPS 324.01 is renumbered SPS 324.01 (1) and amended to read:
SPS 324.01 (1)
All electrical wiring, installations, equipment
,
and materials used in the construction of dwellings shall comply with the requirements of the Wisconsin Administrative Electrical Code, Vol. 2., ch.
SPS 316
, except as provided in sub. (2)
.
SECTION 7.
SPS 324.01 (2)
and (Note) are
created to read:
SPS 324.01 (2)
The requirements in NEC section 210.70(A)(2)(b) do not apply to a stairway for a deck.
Note:
A light over the stairs is not required, but a light outside the door is
.
SECTION 8.
Chapters SPS
3
20 – 325 Appendix is renumbered Chapters SPS
3
20 – 325 Appendix A.
SECTION 9.
Chapters
SPS
3
20
to
325
Appendix
B
is created to read:
NOTE TO LRB:
REVISE PAGINATION ON THE PRESCRIPTIVE DECK STANDARDS CONTENTS TO
MATCH FINAL PAGINATION OF APPENDIX
(See Appendix B in PDF view. Contains multiple images.)
Prescriptive Deck Standards
CONTENTS
Section
Page
1
GENERAL REQUIREMENTS
..…....
1
2
FOOTINGS, AND POST CONNECTIONS
......
…….……..…
3
3
POSTS AND POST-TO-BEAM CONNECTIONS
......
…….......……
4
4
BEAMS
...
……
………
………....
....
.
4
5
JOISTS
...
……
……
.……….……....
6
6
JOIST-TO-BEAM
CONNECTIONS
…...
….…
….
……
8
Section
Page
7
JOIST HANGERS
…………………………8
8
LEDGER ATTACHMENTS
...……
…
.......
9
9
LEDGER-BOARD FASTENERS
....
…......
11
10
FREE-STANDING DECKS
...
…
.…
…
…..
13
11
LATERAL SUPPORT
...
…..........…
….
…
14
12
DECKING
…
…………
……
….
…
….…..
16
13
GUARD AND POSTS
…
..…
…
…….
.
....
...
17
14
STAIRS
...
…………
…
…
…
……............
19
1
5
FRAMING PLAN
.
.
....
…
…
…....
....
...........
22
(See PDF for Figure)
SECTION
:
GENERAL
REQUIREMENTS
1. All l
umber
, 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 certifi
cate 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.
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 ⅛-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, ½
-inch-
diameter bolts and lag screws are specified for various connections.
Edge distance and spacing requirements are based on ½
-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, l
ook 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 d
eck
must
have an electrical outlet along the perimeter of the deck and within 6.5 feet of the floor
in accordance with NEC section 210.52(E)(3)
.
See chapter 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:
Se
e 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 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
.
S
teel plate
s
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 b
earing
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
|
|
Post Spacing
(Measured
Center
to
Center)
|
|
|
4'
|
5'
|
6'
|
7'
|
8'
|
9'
|
10'
|
11'
|
12'
|
13'
|
14'
|
Joist
Length
|
6'
|
Corner
Footing
|
8
|
9
|
10
|
11
|
11
|
12
|
12
|
13
|
14
|
14
|
15
|
|
|
|
Intermediate
Footing
|
10
|
11
|
12
|
13
|
14
|
15
|
15
|
16
|
17
|
17
|
18
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
|
|
7'
|
Corner
Footing
|
9
|
10
|
11
|
11
|
12
|
13
|
13
|
14
|
15
|
15
|
16
|
|
|
|
Intermediate
Footing
|
11
|
12
|
13
|
14
|
15
|
16
|
17
|
17
|
18
|
19
|
19
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
|
|
8'
|
Corner
Footing
|
10
|
10
|
11
|
12
|
13
|
14
|
14
|
15
|
15
|
16
|
17
|
|
|
|
Intermediate
Footing
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
19
|
20
|
21
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
|
|
9'
|
Corner
Footing
|
10
|
11
|
12
|
13
|
14
|
14
|
15
|
16
|
16
|
17
|
18
|
|
|
|
Intermediate
Footing
|
12
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
20
|
21
|
22
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
8
|
|
|
10'
|
Corner
Footing
|
10
|
12
|
12
|
13
|
14
|
15
|
16
|
16
|
17
|
18
|
18
|
|
|
|
Intermediate
Footing
|
13
|
14
|
15
|
17
|
18
|
19
|
20
|
21
|
21
|
22
|
23
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
8
|
10
|
|
|
11'
|
Corner
Footing
|
11
|
12
|
13
|
14
|
15
|
16
|
16
|
17
|
18
|
19
|
19
|
|
|
|
Intermediate
Footing
|
13
|
15
|
16
|
17
|
19
|
20
|
21
|
22
|
22
|
23
|
24
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
10
|
10
|
|
|
12'
|
Corner
Footing
|
11
|
12
|
14
|
15
|
15
|
16
|
17
|
18
|
19
|
19
|
20
|
|
|
|
Intermediate
Footing
|
14
|
15
|
17
|
18
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
|
|
13'
|
Corner
Footing
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
19
|
20
|
21
|
|
|
|
Intermediate
Footing
|
14
|
16
|
17
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
26
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
|
|
14'
|
Corner
Footing
|
12
|
13
|
15
|
16
|
17
|
18
|
18
|
19
|
20
|
21
|
22
|
|
|
|
Intermediate
Footing
|
15
|
17
|
18
|
19
|
21
|
22
|
23
|
24
|
25
|
26
|
27
|
|
|
|
Footing
Thickness
|
6
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
10
|
|
|
15'
|
Corner
Footing
|
12
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
22
|
22
|
|
|
|
Intermediate
Footing
|
15
|
17
|
19
|
20
|
21
|
23
|
24
|
25
|
26
|
27
|
28
|
|
|
|
Footing
Thickness
|
6
|
6
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
10
|
12
|
|
|
16'
|
Corner
Footing
|
13
|
14
|
15
|
17
|
18
|
19
|
20
|
20
|
21
|
22
|
23
|
|
|
|
Intermediate
Footing
|
16
|
18
|
19
|
21
|
22
|
23
|
25
|
26
|
27
|
28
|
29
|
|
|
|
Footing
Thickness
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
12
|
12
|
1
All footing sizes are base diameters
2
.
2
For square footings, insert the diameter (d) into the following formula: √((d/2)
2
x π). This number will give you the square dimension and
must
be rounded up to the
nearest inch.
3
Joist l
ength is the joist span plus any overhang beyond a beam. See section 5.4.
(See PDF for Figure)
Figure
1
FOOTINGS
|
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
|
4x4
|
6
'
|
4x6
|
8'
|
6x6
|
14'
|
2.
Any post supporting a beam splice must be a minimum of 6x6.
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.
(See PDF for Figure)
Figure 2
POST-TO-BEAM CONNECTIONS
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 two 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.
(See PDF for Figure)
Figure
3
BEAM TYPES
1
The maximum length of the overhang is equal to one-fourth of the actual beam span length (0.25 x beam span).
Table 3
A
MAXIMUM BEAM-SPAN LENGTH
1
FOR
DOUGLAS FIR
/
LARCH
3
, HEM/
FIR
3
, S
PRUCE/PINE/FIR (SPF)
3
, WESTERN CEDAR
, PONDEROSA PINE
4
,
AND
RED PINE
4
Joist Span
|
(Number of Plies) Beam Size
2
– 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
"
|
1
1
'-
5
"
|
7
'-
4
"
|
9
'-
8
"
|
12
'-
0
"
|
1
3
'-
11
"
|
≤
8'
|
4
'-
8
"
|
5
'-
11
"
|
7
'-
3
"
|
8
'-
5
"
|
5
'-
6
"
|
7
'-
3
"
|
8
'-
7
"
|
9
'-
11
"
|
6
'-
8
"
|
8
'-6"
|
1
0
'-
5
"
|
1
2
'-
1
"
|
≤
10'
|
4
'-
2
"
|
5
'-
4
"
|
6
'-
6
"
|
7
'-
6
"
|
4
'-
11
"
|
6
'-6"
|
7
'-
8
"
|
8
'-10"
|
6'-
0
"
|
7
'-
7
"
|
9
'-
4
"
|
1
0
'-
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"
|
1
Spans 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
.
2
Beam depth must be equal to or greater than joist depth if joist hangers are used (see Figure 8, Option 3).
3
Incising is assumed.
4
Design values based on northern species with no incising assumed
.
Table 3
B
MAXIMUM BEAM-SPAN LENGTH FOR SOUTHERN PINE
1
Joist Span
|
(Number of Plies) Beam Size
2
– 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"
|
1
Spans 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.
2
Beam 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
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 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.
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.
(See PDF for Figure)
Figure
5
JOISTS WITH DROPPED BEAM – DECK ATTACHED AT HOUSE
1
The 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.)
1
The maximum length of the overhang is equal to one-fourth of the actual joist span length (0.25 x joist span).
T
able
4
MAXIMUM JOIST-
SPAN LENGTH
1
Joist Spacing
(on center)
|
Joist Size
|
Douglas Fir/
Larch,
Hem/
Fir, SPF
2
|
Southern Pine
|
|
|
|
Without Overhang
|
With Overhangs
|
Without Overhang
|
With Overhangs
|
12"
|
2x6
|
9’-1”
|
8’-1”
|
9'-
6
"
|
8
'-
7
"
|
12"
12"
|
2x8
|
12'-
6"
|
9'-
5"
|
13'-1"
|
10'-1"
|
|
|
2x10
|
15'-
8"
|
13'
-
7"
|
16'-2"
|
14'-6"
|
|
|
2x12
|
18'-
0"
|
18'
-0"
|
18'-0"
|
18'-0"
|
16"
|
2x6
|
8’-3”
|
8’-0”
|
8
'-
7
"
|
8
'-
7
"
|
|
|
2x8
|
11'-
1"
|
9'-
5"
|
11'-10"
|
10'-1"
|
|
|
2x10
|
13'-
7"
|
13'
-
7"
|
14'-0"
|
14'-0"
|
|
|
2x12
|
15'
-9"
|
15'
-9"
|
16'-6"
|
16'-6"
|
24"
|
2x6
|
6’-9”
|
6’-9”
|
7'-
6
"
|
7
'-
6
"
|
|
|
2x8
|
9'-
1"
|
9'-
1"
|
9'-8"
|
9'-8"
|
|
|
2x10
|
11'-1"
|
11'-1"
|
11'-5"
|
11'-5"
|
|
|
2x12
|
12'
-10"
|
12'
-10"
|
13'-6"
|
13'-6"
|
1
Spans 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.
2
Incising
is assumed.
SECTION 6:
JOIST-TO-BEAM CONNECTIONS
J
oist
s
must
be attached to beam
s
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.
(See PDF for Figure)
Figure
8
JOIST-TO-BEAM CONNECTION
S
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 j
oist 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.
(See PDF for Figure)
Figure 9
JOIST HANGERS
Table 5
JOIST HANGER DOWNLOAD
Joist Size
|
Minimum Capacity, lbs
|
2x6
|
500
|
2x8
|
5
00
|
2x10
|
6
00
|
2x12
|
7
00
|
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 2x8.
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-
j
oists
.
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
support
ing a deck. If a minimum 1-inch EWP or 2x band board is not present, then a free-standing deck is required, as addressed in section 10.
Figure
1
0
: WOOD I-JOISTS
(See PDF for Figure)
Manufactured wood truss
es.
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 2x4 lumber “ribbon”
board
at the ends of the trusses to tie the ends of the trusses together
(see Detail 1 in section
7
of 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
f
lashing
.
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 a
luminum in direct contact with lumber treated with preservatives that contain copper
, such as ACQ, c
opper
a
zole, or ACZA.
(See PDF for Figure)
F
igure 11
ATTACHMENT
OF
LEDGER BOARD
TO
BAND BOARD
OR BAND JOIST
(See PDF for Figure)
F
igure 12
ATTACHMENT
OF
LEDGER BOARD
TO
SOLID FOUNDATION
(See PDF for Figure)
Figure
1
3
ATTACHMENT
OF
LEDGER BOARD
TO HOLLOW
FOUNDATION
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.
(See PDF for Figure)
Figure
14
PROHIBITED LEDGER ATTACHMENTS
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.
(See PDF for Figure)
Figure 15
LEDGER BOARD FASTENER SPACING AND CLEARANCES
Table 6
LEDGER BOARD FASTENER SPACING, ON CENTER
1,2,3
|
Fastener
|
Band Board
|
Joist Span
:
less than or equal to
|
|
|
|
6'
|
8'
|
10'
|
12'
|
14'
|
16'
|
18'
|
Lag s
crew
s
|
1" EWP
1
1
/
8
" EWP
2x
Lumber
|
24"
28"
30"
|
18"
21"
23"
|
14"
16"
18"
|
12"
14"
15"
|
10"
12"
13"
|
9"
10"
11"
|
8"
9"
10"
|
Through-Bolts
|
1" EWP
1
1
/
8
" EWP
2x
Lumber
|
24"
28"
36"
|
18"
21"
36"
|
14"
16"
34"
|
12"
14"
29"
|
10"
12"
24"
|
9"
10"
21"
|
8"
9"
19"
|
Through-Bolts
with
½" stacked washers
4
,
5
|
2x
Lumber
|
36"
|
36"
|
29"
|
24"
|
21"
|
18"
|
16"
|
Adhesive anchors
|
______
|
32"
|
32"
|
32"
|
24"
|
24"
|
16"
|
16"
|
1
These
values are valid for deck ledgers consisting of
d
ouglas
fir/larch,
hem/f
ir
, or
southern p
ine; and for band boards consisting of
douglas fir-larch
,
hem-fir
, spruce-pine-fir,
southern pine,
or engineered wood product (EWP).
2
Where
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.
The
se
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
½"
.
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
½
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
a
nchors
.
E
xpansion 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
½
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
a
nchors
.
Approved adhesive anchors with a ½-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
s
crews
.
The diameter, length, and shank of l
ag screws
must
comply with Figure 16. Lag screws must be equipped with washers and be installed in the following sequence:
1.
Drill a ½-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.
Ti
ghten each la
g screw snugly, but do not over-
tighten so as to cause wood damage
.
(See PDF for Figure)
Figure 16
LAG SCREW
SECTION 10: FREE-STANDING DECKS
A deck
that
is
free-standing do
es
not utilize the exterior wall of the existing house to support vertical loads.
Instead, a
n 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.
(See PDF for Figure)
Figure 17
FREE-STANDING DECK
SECTION 11: LATERAL SUPPORT
A deck that is more than 24
inches above grade must resist lateral load
s
in accordance with the following:
Diagonal Bracing
.
Provide diagonal bracing both parallel and perpendicular to the beam a
t 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:
B
racing
is not required
perpendicular to the house
for a d
eck
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
.
F
or 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.
(See PDF for Figure)
Figure 18
DIAGONAL BRACING REQUIREMENTS
(See PDF for Figure)
Figure 19
TENSION-TIE CONNE
CTION, WITH LEDGER BOARD
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
D
TT1
Z
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 separat
ing
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 si
ll 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 ½-inch threaded rod, with a withdrawal capacity of at least 750 pounds. The anchor
must
be installed
in accordance with the
manufacturer’
s instructions
.
(See PDF for Figure)
Figure 20
HOLD-DOWN TENSION DEVICE, WITH LEDGER BOARD
Hold-down tension devices.
Hold-
down tension devices
, if used
instead of perpendicular bracing
as
described above
,
must
be provided in
at least
two locations per deck, and each device
must have an allowable-stress-
design capacity of
at least
1,
500 pounds.
Free-standing deck
–
a
ttachment to
h
ouse
.
Attach the deck
’s
rim joist to the existing house exterior wall as shown in Figure 2
1
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 wit
h the flashing provisions in section 8
.
(See PDF for Figure)
Figure 21
ATTACHMENT OF FREE-STANDING DECK TO HOUSE FOR
LATERAL SUPPORT
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 ⅛-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.
(See PDF for Figure)
Figure 22
TYPICAL DECKING
(See PDF for Figure)
Figure 23
RIM JOIST CONNECTION
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” 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 3½
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.
(See PDF for Figure)
Figure 24
GUARDS
Guard
posts.
Guard posts
must
be attached to the deck structure in accordance with
all of
the
following:
1.
Notching guard posts, as shown in
Figure 25
, is prohibited.
2.
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.
3.
Hold-down anchors
must have a minimum capacity of 1,800 pounds.
4.
Guard posts may be attached to either side of the
end
joist or
rim
joist
.
5.
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.
(See PDF for Figure)
Figure 25
POST NOTC
H
ING PROHIBITED
(See PDF for Figure)
Figure 26
GUARD POST TO
END
JOIST
(See PDF for Figure)
Figure 26
GUARD POST TO
RIM
JOIST
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 4½
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,
can
not be less than 3
1½
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 in F
igure 27
.
Figure 27
TREADS AND RISERS
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 l
anding width
must
equal or exceed
the total width of the stairway
it serves.
Stair
s
tringers
.
Stringers must
comply with all of the following:
1.
Stringers must be sawn or solid 2x12s 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 ½ 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 e
xception:
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 4x4 post may be provided to support the stringer and shorten its span length.
The 4x4 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
.
(See PDF for Figure)
Figure 28
STRINGER BEARING
L
OWER BEARING AT FOOTING
L
OWER BEARING AT FOOTING – FROST PROTECTED
(See PDF for Figure)
Figure 29
STAIR OR POST FOOTING
(See PDF for Figure)
Figure 30
STRINGER SPAN LENGTH
Tread and r
iser
m
aterial
.
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 3
0.
3.
R
isers
that are not open (as shown in Figure 27)
must
be framed with 1x lumber minimum or
an manufacturer recommended
wood-plastic composite.
(See PDF for Figure)
Figure 3
1
STAIRWAY TREADS
Table 7
MINIMUM TREAD SIZES
1
Species
|
Cut Stringer
|
Solid Stringer
|
Douglas Fir/Larch, Hem/Fir, SPF
2
|
2x4 or 5/4
|
2x8 or 3x4
|
Southern Pine
|
2x4 or 5/4
|
2x8
|
Redwood, Western Cedars, Ponderosa Pine
3
, Red Pine
3
|
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.
Gu
ards must be provided on all open sides of stairs consisting of more than 3 risers. Stair guards must compl
y with section 13 and Figure 32.
(See PDF for Figure)
Figure 32
STAIR GUARDS
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 h
andrail
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 h
andrail must have a smooth surface with no sharp corners and must be graspable, as
shown in Figure 3
4. Recessed sections may be shaped from a 2x6 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
.
(See PDF for Figure)
Figure 3
3
STAIR HANDRAILS
(See PDF for Figure)
Figure 3
4
HANDRAIL GRASPABILITY
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 o
f the ledger board fasteners. You can u
se the sample typical deck framing plan shown
on the next page
in combination with
the requirements
in
this document to complete your deck.
(See PDF for Figure)
Figure 3
5
TYPICAL DECK FRAMING PLAN
Decking:
2x4
2x6
five-quarter board
wood-plastic composite (per ASTM D 7032)
Other decking, evaluation report number:
Joists:
size:
2x6
2x8
2x10
2x12
spacing:
12 in.
16 in.
24 in.
joist span dimension:
ft. -
in.
overhang:
Yes
No
overhang dimension:
ft. -
in.
rim joist:
2x6
2x8
2x10
2x12
Beam(s):
number of plies:
2
3
size:
2x6
2x8
2x10
2x12
overhang:
Yes
No
overhang dimension:
ft. -
in.
Posts:
size:
4x4
4x6
6x6
height:
ft. -
in.
Footings:
size:
in.
square
round
thickness:
in.
Ledger:
ledger board size:
2x8
2x10
2x12
Not applicable (free-standing deck)
fastener:
Through bolt
Lag screw
Wood screw
Expansion anchor
Adhesive anchor
Lateral support:
Tension-tie
Diagonal bracing, size:
2x
(not permitted for free-standing deck)
Deck size:
L=
ft. -
in.
W=
ft. -
in.
SECTION 10.
Chapters
SPS 320
to
325
Appendix
C
is created to read:
Supplemental D
eck
Features and Reference Information
CONTENTS
1.
Wood
preservatives for ground contact.
2.
Specifications for fasteners.
3.
Sources of design values.
4.
Joist spans for alternate wood species.
5.
Framing around a chimney or bay window.
6.
Attachment of ledger boards to metal-plate-connected wood
floor trusses.
1. Wood
preservatives for ground contact.
The following Table lists common pressure-preservative treatments and retention levels, in pounds per cubic foot, for sawn lumber in ground contact –
based on the American Wood Protection Association
’s
Book of Standards
.
Table C
–
1
PRESERVATIVE TREAT
MENTS AND RETENTION LEVELS
FOR
GROUND CONTACT
(IN POUNDS PER CUBIC FOOT)
Species
|
ACQ-B
|
ACQ-C
|
ACQ-D
|
CA-B
|
CuN-W
|
Southern Pine
|
0.40
|
0.40
|
0.40
|
0.21
|
0.11
|
Douglas Fir-Larch
|
0.40
|
0.40
|
NR
|
0.21
|
0.11
|
Hem-Fir
|
0.40
|
0.40
|
0.40
|
0.21
|
0.11
|
Ponderosa Pine
|
0.40
|
0.40
|
0.40
|
0.21
|
0.11
|
Red Pine
|
0.40
|
0.40
|
0.40
|
0.21
|
0.11
|
Spruce-Pine-Fir
|
NR
1
|
0.40
|
NR
|
NR
|
NR
|
Redwood
|
NR
|
NR
|
NR
|
NR
|
NR
|
1
NR = t
reatment
n
ot
r
ecommended.
2. Sources of design values.
The sources of the design values in Appendix B are as follows:
Table 1 – Minimum footing sizes: The Building Inspectors Association of Southeast Wisconsin, December 2014.
Table 2 – Maximum post heights:
Typical Deck Details
,
Based on the 2009 International Residential Code
, Fairfax County, Virginia, July 2013.
Tables 3A and 3B – Maximum beam spans:
Design for Code Acceptance 6,
American Wood Council, May 2013.
Table 4 – Maximum joist spans:
Design for Code Acceptance 6
(DCA 6), American Wood Council, May 2013; except for the 2x6 values, which are from t
he Building Inspectors Association of Southeast Wisconsin, December 2014.
Table 5 – Minimum joist-hanger download capacity:
Design for Code Acceptance 6,
American Wood Council, May 2013;
except for the 2x6 values
, which are repeated from the 2x8 values.
Table 6 – Ledger-board-fastener spacing:
Design for Code Acceptance 6,
American Wood Council, May 2013
.
Figure 29 – Stringer span length, and Table 7 – Minimum tread sizes:
Design for Code Acceptance 6,
American Wood Council, May 2013
.
Table C–2 – Maximum joist spans for
redwood, western cedars, ponderosa pine, and red pine
:
Design for Code Acceptance 6,
American Wood Council, May 2013; except for the 2x6 values, which are from the Building Inspectors Association of Southeast Wisconsin, December 2014.
Table C–3 – Trimmer joist download capacity:
Design for Code Acceptance 6,
American Wood Council, May 2013.
3. Joist spans for
alternate wood species.
The following Table lists maximum joist-span lengths for
redwood, western cedars, ponderosa pine,
and
red pine
.
Table
C–2
MAXIMUM JOIST-SPAN LENGTH
1
FOR
REDWOOD,
WESTERN CEDARS, PONDEROSA PINE
2
,
AND RED PINE
2
Joist Spacing
(on center)
|
Joist Size
|
Without Overhang
|
With Overhangs
|
|
|
2x6
|
8
'-
5
"
|
7
'-
3
"
|
12"
|
2x8
|
1
1
'-
8
"
|
8
'-
6
"
|
|
|
2x10
|
1
4
'-
11
"
|
12
'-
3
"
|
|
|
2x12
|
1
7
'-
5
"
|
16
'-
5
"
|
16"
|
2x6
|
7
'-
8
"
|
7
'-
3
"
|
|
|
2x8
|
10
'-
7
"
|
8
'-
6
"
|
|
|
2x10
|
1
3
'-0"
|
1
2
'-
3
"
|
|
|
2x12
|
1
5
'-
1
"
|
15
'-
1
"
|
24"
|
2x6
|
6
'-
7
"
|
6
'-
7
"
|
|
|
2x8
|
8
'-8"
|
8
'-
6
"
|
|
|
2x10
|
10
'-
7
"
|
1
0
'-
7
"
|
|
|
2x12
|
1
2
'-
4
"
|
1
2
'-
4
"
|
1
Spans 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.
2
Design values based on northern species with no incising assumed.
4
. Alternate beam and joist spans.
The table
on the following two pages
lists alternate beam and joist spans and corresponding footing sizes from the Southeast Wisconsin Building Inspectors Association that can be used instead of the
values
in Appendix B.
Beam
and
Footing
Sizes
with
Overhangs
Based
on
No.
2
or
better
Southern
Pine,
Douglas
Fir-Larch
2
,
and
Ponderosa
Pine
|
|
|
Post
Spacing
(Measured
Center
to
Center)
|
|
|
4'
|
5'
|
6'
|
7'
|
8'
|
9'
|
10'
|
11'
|
12'
|
13'
|
14'
|
Joist Length (JL)
1
|
6'
|
Southern
Pine
Beam
|
1-2x6
|
1-2x6
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x6
|
1-2x8
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x10
|
3-2x12
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x6
|
1-2x8
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x10
|
3-2x12
|
|
|
|
Corner
Footing
|
8
|
7
|
6
|
9
|
8
|
7
|
10
|
8
|
7
|
11
|
9
|
8
|
11
|
9
|
8
|
12
|
10
|
9
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
11
|
10
|
14
|
12
|
10
|
15
|
12
|
10
|
|
|
|
Intermediate
Footing
|
10
|
8
|
7
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
15
|
13
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
17
|
14
|
13
|
18
|
15
|
13
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
|
|
7'
|
Southern
Pine
Beam
|
1-2x6
|
1-2x8
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x6
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
3-2x12
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x6
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
|
|
|
Corner
Footing
|
9
|
7
|
7
|
10
|
8
|
7
|
11
|
9
|
8
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
13
|
11
|
10
|
14
|
12
|
10
|
15
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
|
|
|
Intermediate
Footing
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
17
|
14
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
19
|
16
|
14
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
|
|
8'
|
Southern
Pine
Beam
|
1-2x6
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x6
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x6
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
3-2x12
|
Eng
Bm
|
|
|
|
Corner
Footing
|
10
|
8
|
7
|
10
|
9
|
8
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
11
|
10
|
14
|
12
|
10
|
15
|
12
|
11
|
15
|
13
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
|
|
|
Intermediate
Footing
|
12
|
10
|
8
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
19
|
16
|
14
|
20
|
16
|
14
|
21
|
17
|
15
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
|
|
9'
|
Southern
Pine
Beam
|
1-2x6
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x10
|
3-212
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
10
|
8
|
7
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
18
|
14
|
13
|
|
|
|
Intermediate
Footing
|
12
|
10
|
9
|
14
|
11
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
20
|
16
|
14
|
20
|
17
|
15
|
21
|
17
|
15
|
22
|
18
|
16
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
8
|
|
|
10'
|
Southern
Pine
Beam
|
1-2x6
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
10
|
9
|
8
|
12
|
10
|
8
|
12
|
10
|
9
|
13
|
11
|
10
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
16
|
14
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
18
|
15
|
13
|
|
|
|
Intermediate
Footing
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
13
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
20
|
16
|
14
|
21
|
17
|
15
|
21
|
18
|
15
|
22
|
18
|
16
|
23
|
19
|
16
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
8
|
10
|
|
|
11'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
11
|
9
|
8
|
12
|
10
|
9
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
11
|
16
|
14
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
19
|
16
|
14
|
|
|
|
Intermediate
Footing
|
13
|
11
|
10
|
15
|
12
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
19
|
15
|
13
|
20
|
16
|
14
|
21
|
17
|
15
|
22
|
18
|
15
|
22
|
18
|
16
|
23
|
19
|
17
|
24
|
20
|
17
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
10
|
10
|
|
|
12'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
11
|
9
|
8
|
12
|
10
|
9
|
14
|
11
|
9
|
15
|
12
|
10
|
15
|
13
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
19
|
16
|
14
|
20
|
17
|
14
|
|
|
|
Intermediate
Footing
|
14
|
12
|
10
|
15
|
13
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
16
|
14
|
20
|
17
|
15
|
21
|
18
|
15
|
22
|
18
|
16
|
23
|
19
|
17
|
24
|
20
|
17
|
25
|
21
|
18
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
Beam
and
Footing
Sizes
with
Overhangs
Based
on
No.
2
or
better
Southern
Pine,
Douglas
Fir-Larch
2
,
and
Ponderosa
Pine
|
|
|
Post
Spacing
(Measured
Center
to
Center)
|
|
|
4'
|
5'
|
6'
|
7'
|
8'
|
9'
|
10'
|
11'
|
12'
|
13'
|
14'
|
Joist
Length
(JL)
1
|
13'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
12
|
10
|
8
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
12
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
19
|
16
|
14
|
20
|
17
|
14
|
21
|
17
|
15
|
|
|
|
Intermediate
Footing
|
14
|
12
|
10
|
16
|
13
|
12
|
17
|
14
|
13
|
19
|
15
|
13
|
20
|
16
|
14
|
21
|
17
|
15
|
22
|
18
|
16
|
23
|
19
|
17
|
24
|
20
|
17
|
25
|
21
|
18
|
26
|
21
|
19
|
|
|
|
Footing
Thickness
|
6
|
6
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
|
|
14'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
12
|
10
|
9
|
13
|
11
|
10
|
15
|
12
|
10
|
16
|
13
|
11
|
17
|
14
|
12
|
18
|
14
|
13
|
18
|
15
|
13
|
19
|
16
|
14
|
20
|
17
|
14
|
21
|
17
|
15
|
22
|
18
|
15
|
|
|
|
Intermediate
Footing
|
15
|
12
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
16
|
14
|
21
|
17
|
15
|
22
|
18
|
16
|
23
|
19
|
16
|
24
|
20
|
17
|
25
|
21
|
18
|
26
|
21
|
19
|
27
|
22
|
19
|
|
|
|
Footing
Thickness
|
6
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
10
|
|
|
15'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
2-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
12
|
10
|
9
|
14
|
11
|
10
|
15
|
12
|
11
|
16
|
13
|
12
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
16
|
14
|
20
|
16
|
14
|
21
|
17
|
15
|
22
|
18
|
15
|
22
|
18
|
16
|
|
|
|
Intermediate
Footing
|
15
|
13
|
11
|
17
|
14
|
12
|
19
|
15
|
13
|
20
|
17
|
14
|
21
|
18
|
15
|
23
|
19
|
16
|
24
|
20
|
17
|
25
|
21
|
18
|
26
|
21
|
19
|
27
|
22
|
19
|
28
|
23
|
20
|
|
|
|
Footing
Thickness
|
6
|
6
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
10
|
12
|
|
|
16'
|
Southern
Pine
Beam
|
1-2x8
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Douglas
Fir-Larch
Beam
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x10
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Ponderosa
Pine
Beam
|
2-2x6
|
2-2x8
|
2-2x10
|
2-2x12
|
3-2x12
|
3-2x12
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
Eng
Bm
|
|
|
|
Corner
Footing
|
13
|
11
|
9
|
14
|
12
|
10
|
15
|
13
|
11
|
17
|
14
|
12
|
18
|
15
|
13
|
19
|
15
|
13
|
20
|
16
|
14
|
20
|
17
|
15
|
21
|
18
|
15
|
22
|
18
|
16
|
23
|
19
|
16
|
|
|
|
Intermediate
Footing
|
16
|
13
|
11
|
18
|
15
|
13
|
19
|
16
|
14
|
21
|
17
|
15
|
22
|
18
|
16
|
23
|
19
|
17
|
25
|
20
|
18
|
26
|
21
|
18
|
27
|
22
|
19
|
28
|
23
|
20
|
29
|
24
|
21
|
|
|
|
Footing
Thickness
|
6
|
8
|
8
|
8
|
8
|
10
|
10
|
10
|
10
|
12
|
12
|
Notes:
Joist
Length
(J
) is
Joist
Span
(L
)
plus
any cantilever
at
the
beam
2000
psf
Soil
3
L
J
that
is
being
sized.
3000
psf
Soil
3
Incising assumed
for
refractory
species
Douglas
Fir-Larch.
4000
psf
Soil
3
All
footing
sizes
above
are
base
diameters
(in
inches)
and
are
listed
for
THREE
SOIL
CAPACITIES.
Soil
capacity
is
based
on
the requirements
of
State
of
Wisconsin SPS
321.15
(3).
4
For
square
footings,
insert
the
diameter
(d)
into
the
following
formula:
√((d/2)
2
x
π).
This
number
will
give
you the
square
dimension
and
shall
be
rounded
up
to
the
nearest
inch.
|
5. Framing around a chimney or bay window.
All members at a chimney or bay window
must
be framed in accordance with Figure
C–1
.
Headers may span a maximum of 6'-0".
Where
a chimney or bay window is wider than 6'-0", one or more 6x6 posts may be added to reduce header spans to less than 6'-0".
In such cases, the post footing mu
st meet the requirements in
section
2 of Appendix B
.
Plan submittal and approval is required for h
eaders with a span length greater than
6'-0"
.
Headers
must
be located no more than
3'-0"
from the end of the trimmer joist.
Triple trimmer joists are required on each side of the header if joist spacing is 12
"
or 16
"
o.c. or if the trimmer joist span exceeds 8
'
-6
"; otherwise, double trimmer joists are permitted
.
Trimmer joists may bear on the beam and extend past the beam centerline up to L
J
/4 as shown in Figures
5 and 7 in Appendix B
, or the trimmer joist may attach to the side of the beam with joi
st hangers as shown in Figure 6 in Appendix B
.
Joist hangers
must
each have a minimum download capacity in accordance with Table
C–3
.
Bolts or lag screws used to attach the hanger to the ledger
must
fully extend through the ledger into the
2-inch nominal lumber band joist (1½" actual) or
the
EWP rim board.
See Figure 15 in Appendix B for fastener spacing, and edge and end distances.
Otherwise a free
-
standing deck is required.
(See PDF for Figure)
Figure C–1
DETAIL FOR FRAMING AROUND A CHIMNEY OR BAY WINDOW
Table C–3
TRIMMER JOIST HANGER DOWNLOAD CAPACITY
Joist Size
|
Minimum Capacity, lbs
|
2x8
|
1050
|
2x10
|
1380
|
2x12
|
1500
|
6
.
Attachment of l
edger boards
to
metal-plate-connected wood
floor trusses
.
The
research report on the following pages shows acceptable methods for a
ttach
ing
a
ledger board to
a
metal-pl
ate-connected wood-floor-truss system
.
File reference: SPS 320-325/Rules decks
11_department
(
Page intentionally skipped.)
Attachment of Resident
i
al Deck Ledger to
Metal Plate Connected Wood Truss Floor System
SRR No.
1408-01
Prepared
for SBCA
Report Written
by:
Jim Vogt, P.E.
October 1, 2014
Table of Contents
Introduction
page
3
Key Definitions
page
3
Background
page
3
Application
page
4
Installation
page
4
Findings
page
11
References and Substantiating Data
page
11
Introduction
:
This research report provides construction details for residential deck ledger attachment to metal plate connected wood truss floor systems. The applicable codes and standards follow the
2009
and
2012 International Building Code
(
IBC
) and the
2009
and
2012 International Residential Code
(
IRC
)
.
Proper attachment of the deck ledger to the house is critical for ensuring that an “attached” deck is safely and securely supported at this location.
This report provides details for attaching a 2
"
nominal lumber deck ledger to residential floor systems constructed with metal plate connected wood (MPCW) floor trusses
.
Key
D
efinitions
:
Deck
Ledger
–
A horizontal lumber beam attached to an existing wall and used to tie in construction elements such as porch roofs and decks. A deck ledger is installed as part of the deck fr
ame construction and supports one
end of the deck
joists.
Truss
– An engineered structural component, assembled from wood members, metal connector plates and other mechanical fasteners, designed to carry its own weight and superimposed design loads. The truss members form a semi-rigid structural framework and are assembled such that the members form triangles
.
Wood Structural Panel
(WSP) – A panel manufactured from wood veneers, strands or wafers or a combination of veneer and wood strands or wafers bonded together with waterproof synthetic resins or other suitable bonding systems. Examples include: plywood, Oriented Strand Board (OSB), waferboard and composite panels.
Background
:
The
2009
and
2012
IRC
include
prescriptive provis
ions for attaching a 2" nominal lumber deck ledger to a 2" nominal lumber band joist bearing directly on a sill plate or wall plate using
½"-diameter bolts or lag screws.
AF&PA’s American Wood Council, in cooperation with the International Code Council, has also developed
Design for Code Acceptance No. 6
(
DCA6
) –
Prescriptive Residential Deck Construction Guide
, available at
awc.org
.
The prescriptive provisions
for the deck ledger connection to the band joist
in the
IRC
and
DCA6
are based on the results from a series of ultimate load tests conducted at
Virginia Polytechnic Institute and State University
(VT)
Department of Wood Scien
ce and Forest Products,
and Washington State University (WSU)
Wood Materials and Engineering Laboratory
. This testing
evaluated the capacity
2" nominal
pressure-preservative-treated
(PPT)
H
em-
F
ir (HF) and
S
outhern
P
ine (SP) ledgers attached to either
2" nominal
S
pruce-
P
ine-
F
ir (SPF) or 1
" net
Douglas-
F
ir (DF) laminated veneer lumber (LVL) band joists, through
15
/
32
"-
thick oriented strand board (OSB) sheathing, with ½
"
-diameter
hot-dipped galvanized (HDG)
bolts or lag screws
, meeting the requirements
of ANSI/ASME Standard B18.2.1
.
The
deck ledger
assemblies evaluated at VT and WSU were deemed to represent commonly accepted means of connecting deck ledgers to band joints that cannot be evaluated using the provisions of the
National Design Specification
for Wood Construction
(
NDS
)
because:
1.
T
he ledger is not in direct contact with the band joist (i.e., separated by
15
/
32
" OSB sheathing)
.
2.
T
he minimum required penetration depth of four diameters (4D) is not met when using ½"-diameter lag screws into an 1
1
/
2
"
-
thick band joist.
Application:
The details and fastener spacing tables provided in this report for connecting a 2" nominal lumber deck ledger to a residential floor system constructed with MPCW trusses use a single shear reference lateral design value, Z, of 710 lbs. for a ½"-diameter bolt and 375 lbs. for a ½" x 6" lag screw. These lateral design values were developed from the VT and WSU testing, and assume the fasteners are installed in accordance with the
NDS
requirements for clearance holes, lead holes, edge distance and end distance.
Detail 1
includes construction information for attaching 2" nominal lumber deck ledgers to the ends of MPCW floor trusses spaced no more than 24" o.c.
Table 1
provides the maximum on-center spacing for each ½"-diameter bolt or ½" x 6" lag screw used to attach the ledger to the floor truss system for deck joist spans up to 18', assuming a design deck load of 40 psf live load (or 40 psf snow load) and 10 psf dead load.
Table 2
includes similar information as
Table 1
, except for a design deck load of 60 psf live load (or 60 psf snow load) and 10 psf dead load.
Detail 2
includes construction information for attaching 2" nominal lumber deck ledgers to the side of a MPCW floor ladder frame with 4x4 vertical webs spaced no more than 16" o.c.
Table 3
provides the maximum on-center spacing for each ½"-diameter bolt and ½" x 6" lag screw used to attach the ledger to the ladder frame for deck joist spans up to 18', assuming a design deck load of 40 psf live load (or 40 psf snow load) and 10 psf dead load.
Table 4
includes similar information as
Table 3
, except for a design deck load of 60 psf live load (or 60 psf snow load) and 10 psf dead load.
Detail 3
includes deck lateral load connection options capable of resisting the 1500 lbf lateral load requirement specified in
2009
and
2012 IRC
Section 507
.
Support of concentrated loads from deck beams of girders are beyond the scope of this report. Deck ledgers shall not be supported on stone or masonry veneer.
Installation
:
The following is a summary of the minimum requirements and limitations
for installing
a 2
" nominal lumber deck ledger with
residential floor systems constructed with MPCW floor trusses.
1.
Ledger must be 2x10 or 2x12 PPT or code
-
approved decay-resistant lumber with a specific gravity, G
>
0.43.
Ledger shall be identified by the grade mark of, or certificate of inspection issued by, an approved lumber grading or inspection bureau or agency. PPT material must be pressure-treated with an approved process in accordance with American Wood Protection Association standards
2.
Install ledger directly over wood structural sheathing (
15
/
32
" maximum thickness) fastened to the wall per the building code.
3.
Attach ledger through wood structural sheathing into 2-ply 2x4 truss end vertical, 4x4 vertical web or key-block with ½
"
x 6
"
lag screws or ½
"
-diameter bolts with washers and nuts.
1.1
Only one (1) fastener into each truss member or key-block.
2.2
Install each fastener through the centerline of the truss member or key-block and position so as not to interfere with bottom and top chord joints and connector plates. Refer to
Detail 1
and
Detail 2
for spacing requirements
3.3
Lag screws and bolts shall be installed according to
2005 NDS
requirements. A "test" installation is recommended before drilling the lead holes
,
to ensure that the lead holes are neither too small nor too large.
½
"
x 6
"
lag screws:
o
Lead holes for the threaded portion shall be
5
/
16
"
.
o
Clearance holes shall be ½
"
and the same depth of penetration as the length of unthreaded shank
.
½
"
-diameter bolts:
o
Holes shall be a minimum of
17
/
32
"
to a maximum of
9
/
16
"
.
All fasteners used with PPT wood shall
be hot-dip
zinc-coated
galvanized
steel, stainless steel, silicon
bronze, or copper. Fasteners to be hot-dipped galvanized shall meet the requirements of
ASTM
A15
3 – 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
". Lag screws, bolts, nuts and washers are permitted to be mechanically deposited zinc-coated steel with coating weights in accordance with
ASTM B695
, Class 55, minimum.
All hardware (e.g., joist hangers, hold-down devise, etc.) shall be galvanized or shall be stainless steel. Hardware to be hot-dipped prior to fabrication shall 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 shall meet
ASTM A123
–
Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products
.
Fasteners and hardware exposed to saltwater or located within 300
'
of a salt water shoreline shall be stainless steel grade 304 or 316.
Fasteners and hardware shall be of the same corrosion-resistant material.
Other coated or non-ferrous fasteners or hardware shall be as approved by the authority having jurisdiction.
4.
Install flashing at top of ledger for water tightness. Flashing shall be corrosion-resistant metal of minimum nominal 0.019
"
thickness or an approved non-metallic material. Do not use aluminum flashing in direct contact with lumber treated with preservatives containing copper, such as ACQ, Copper Azole or ACZA.
5.
Two-ply 2x4 truss end verticals, 4x4 truss vertical webs and key-blocks connected to ledger with lag screws or bolts shall have a specific gravity, G ≥ 0.42 (includes DF, HF, SP and SPF)
.
Construct key-blocks with minimum 2x4 No. 2 or better lumber.
Install key-blocks at required locations. Cut to fit tight.
Refer to
Detail 1
and
Detail 2
for additional information concerning key-block construction and attachment.
Detail 1:
Attachment of Deck Ledger to Floor System with MPCW Trusses
(See PDF for Figure)
Joist Span
|
<
to 6'
|
6'-1" to 8'
|
8'-1" to 10'
|
10'-1" to 12'
|
12'-1" to 14'
|
14'-1" to 16'
|
16'-1" to 18'
|
Connection Details
|
On-center Spacing of Fasteners (in.)
4
|
½"x 6" lag screw with
15
/
32
",max., wood structural panel sheathing
|
24
|
12
5
|
12
5
|
12
5
|
12
5
|
8
6
|
8
6
|
½" diameter bolt with
15
/
32
", max., wood structural panel sheathing
|
24
|
24
|
24
|
24
|
24
|
12
5
|
12
5
|
Ledgers shall be flashed in accordance with applicable building code requirements to prevent water from contacting the exposed wood structural sheathing and floor truss.
Snow load shall not be assumed to act concurrently with live load.
Ledgers must be 2x10 or 2x12 PPT or code-approved decay-resistant lumber with specific gravity, G
>
0.43. Truss 2-ply 2x4 end verticals and key-blocks must have a G
>
0.42.
Stagger lag screws and bolts as shown in
Detail 1
.
Requires key-blocks at 24" o.c., maximum. Attach ledger to 2-ply end vertical of each truss with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 1
for key-block construction and installation information.
Requires two (2) key-blocks at 8" o.c., maximum, between each truss. Attach ledger to 2-ply end vertical of each truss with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 1
for key-block construction and installation information.
|
Table 1:
Deck Ledger Connection to Ends of MPCW Floor Trusses Spaced 24" o.c., Max.
1,2,3
(Deck Live Load = 40 psf, Deck Dead Load = 10 psf, Snow Load
40 psf)
Joist Span
|
<
to 6'
|
6'-1" to 8'
|
8'-1" to 10'
|
10'-1" to 12'
|
12'-1" to 14'
|
14'-1" to 16'
|
16'-1" to 18'
|
Connection Details
|
On-center Spacing of Fasteners (in.)
4
|
½" x 6" lag screw with
15
/
32
",max., wood structural sheathing
|
12
5
|
12
5
|
12
5
|
8
6
|
8
6
|
8
6
|
Use bolted connection
|
½" diameter bolt with
15
/
32
", max., wood structural sheathing
|
24
|
24
|
24
|
12
5
|
12
5
|
12
5
|
12
5
|
1. Ledgers shall be flashed in accordance with applicable building code requirements to prevent water from contacting the exposed wood structural sheathing and floor truss.
2. Snow load shall not be assumed to act concurrently with live load.
3. Ledgers must be 2x10 or 2x12 PPT or code-approved decay-resistant lumber with specific gravity, G
>
0.43. Truss 2-ply 2x4 end verticals and key-blocks must have a G
>
0.42.
4. Stagger lag screws and bolts as shown in
Detail 1
.
5. Requires key-blocks at 24" o.c., maximum. Attach ledger to 2-ply end vertical of each truss with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 1
for key-block construction and installation information.
6. Requires two (2) key-blocks at 8" o.c., maximum, between each truss. Attach ledger to 2-ply end vertical of each truss with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 1
for key-block construction and installation information.
|
Table 2:
Deck Ledger Connection to Ends of MPCW Floor Trusses Spaced 24" o.c., Max.
1,2,3
(Deck Live Load = 60 psf, Deck Dead Load = 10 psf, Snow Load
<
60 psf)
(See PDF for Figure)
Detail 2:
A
ttachment
of
D
eck
L
edger
to
F
loor
S
ystem
with
MPCW T
russes,
W
hen
L
edger
is
I
nstalled
P
arallel
to
T
russ
S
pan
&
S
pacing
of
S
crews
is
L
ess
Than
the
S
pacing
of
the
V
erticals
Joist Span
|
< 6' to 8'
|
8'-1" to 10'
|
10'-1" to 12'
|
12'-1" to 14'
|
14'-1" to 16'
|
16'-1" to 18'
|
Connection Details
|
On-center Spacing of Fasteners (in.)
4
|
½" x 6" lag screw with
15
/
32
",max., wood structural sheathing
|
16
|
16
|
8
5
|
8
5
|
8
5
|
8
5
|
½" diameter bolt with
15
/
32
", max., wood structural sheathing
|
32
|
32
|
16
|
16
|
16
|
16
|
1. Ledgers shall be flashed in accordance with applicable building code requirements to prevent water from contacting the exposed wood structural sheathing and floor truss.
2. Snow load shall not be assumed to act concurrently with live load.
3. Ledgers must be 2x10 or 2x12 PPT or code-approved decay-resistant lumber with specific gravity, G > 0.43. Truss 4x4 vertical web and key-blocks must have a G > 0.42.
4. Stagger lag screws and bolts as shown in
Detail 2
.
5. Requires key-blocks at 16" o.c., maximum. Attach ledger to each 4x4 vertical web with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 2
for key-block construction and installation information.
|
Table 3:
Deck Ledger Connection to Side of MPCW Floor Ladder Frame with 4s4 Vertical Webs Spaced at 16" o.c., Max.
1,2,3
(Deck Live Load = 40 psf, Deck Dead Load = 10 psf, Snow Load
40 psf)
Joist Span
|
< 6' to 8'
|
8'-1" to 10'
|
10'-1" to 12'
|
12'-1" to 14'
|
14'-1" to 16'
|
16'-1" to 18'
|
Connection Details
|
On-center Spacing of Fasteners (in.)
4
|
½" x 6" lag screw with
15
/
32
",max., wood structural sheathing
|
16
|
8
5
|
8
5
|
8
5
|
8
5
|
Use bolted connection
|
½" diameter bolt with
15
/
32
", max., wood structural sheathing
|
32
|
16
|
16
|
16
|
8
5
|
8
5
|
1. Ledgers shall be flashed in accordance with applicable building code requirements to prevent water from contacting the exposed wood structural sheathing and floor truss.
2. Snow load shall not be assumed to act concurrently with live load.
3. Ledgers must be 2x10 or 2x12 PPT or code-approved decay-resistant lumber with specific gravity, G > 0.43. Truss 4x4 vertical web and key-blocks must have a G > 0.42.
4. Stagger lag screws and bolts as shown in
Detail 2
.
5. Requires key-blocks at 16" o.c., maximum. Attach ledger to each 4x4 vertical web with one (1) fastener and to each key-block with one (1) fastener. Refer to
Detail 2
for key-block construction and installation information.
|
Table 4:
Deck Ledger Connection to Side of MPCW Floor Ladder Frame with 4x4 Vertical Webs Spaced at 16" o.c., Max.
1,2,3
(Deck Live Load = 60 psf, Deck Dead Load = 10 psf, Snow Load
60 psf)
(See PDF for Figure)
Detail 3:
Deck
L
ateral Load Connection Capable of Resisting the 1500 lbf Lateral Load Requirement
Specified in
2009
&
2012 IRC
Section 507
1.
N
ailing deck ledgers to
metal plate connected wood truss
floor systems is not sufficient.
The
deck ledger must be
attached to the truss or key-block with lag screws or bolts
. Various options and connection details for achieving the connection
of the deck ledger to the metal plate connected wood truss
floor system are provided in this
report
, which may be referred to by the building designer to achieve a code-conforming deck ledger connection.
IBC
Section
104.11
and
IRC
Section R104.11
(
IFC
Section 104.
9
is similar)
state
:
104.11 Alternative materials, design and methods of construction and equipment
.
The provisions of this code are not intended to prevent the installation of any material or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been
approved
. An alternative material, design or method of construction shall be
approved
where the
building official
finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code
. …
Where the alternative material, design or method of construction is not
approved
, the
building official
shall respond in writing, stating the reasons the alternative was not
approved
.
This
research report
is subject to periodic review and revision.
For the most recent version of this report, visit
sbcindustry.com
.
For information on the current status of this report, contact SBCA.
2.
3.
ANSI/AWC NDS-2012,
ASD/LRFD NDS
;
National Design Specification for Wood Construction
. 2012
;
American Wood Council, 222 Catoctin Circle, SE, Suite 201, Leesburg, VA 20175.
Carradine,
D.M.,
Bender,
D.,
Loferski,
J.R. and
Woeste
, F.E.
2005
;
Residential Deck Ledger Design
;
Building Safety Journal
, December, 2005: (4-7).
Carradine, D.M., Bender, D., Loferski, J.R. and Woeste, F.E. 2006
;
Residential Deck Ledger Connection Testing and Design
;
Structure Magazine
, May, 2008: (53-56).
Design for Code Acceptance, DCA 6, Prescriptive Residential Wood Deck Construction Guide
;
2009
;
American Wood Council, 222 Catoctin Circle, SE, Suite 201, Leesburg, VA 20175.
4.
Woeste, F.E. 2008
;
Safe and Durable Coastal Decks
;
Coastal Contractor
, March/April, 2008: (1-7)
.
SECTION 11.
EFFECTIVE DATE.
The rules adopted in this order shall take effect on the first day of the month following publication in the Wisconsin administrative register, pursuant to s.
227.22 (2) (intro.)
, Stats.
(END OF TEXT OF RULE)
