CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2009 (IRC 2009)

Chapter 1 Scope and Administration

Chapter 2 Definitions

Chapter 3 Building Planning

Chapter 4 Foundations

Chapter 5 Floors

Chapter 6 Wall Construction

Chapter 7 Wall Covering

Chapter 8 Roof-Ceiling Construction

Chapter 9 Roof Assemblies

Chapter 10 Chimneys and Fireplaces

Chapter 11 Energy Efficiency

Chapter 12 Mechanical Administration

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment

Chapter 14 Heating and Cooling Equipment

Chapter 15 Exhaust Systems

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 18 Chimneys and Vents

Chapter 19 Special Fuel-Burning Equipment

Chapter 19 Special Fuel-Burning Equipment

Chapter 20 Boilers and Water Heaters

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 21 Hydronic Piping

Chapter 22 Special Piping and Storage Systems

Chapter 22 Special Piping and Storage Systems

Chapter 23 Solar Systems

Chapter 23 Solar Systems

Chapter 24 Fuel Gas

Chapter 24 Fuel Gas

Chapter 25 Plumbing Administration

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 31 Vents

Chapter 32 Traps

Chapter 32 Traps

Chapter 33 Storm Drainage

Chapter 33 Storm Drainage

Chapter 34 General Requirements

Chapter 34 General Requirements

Chapter 35 Electrical Definitions

Chapter 35 Electrical Definitions

Chapter 36 Services

Chapter 36 Services

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 37 Branch Circuit and Feeder Requirements

Chapter 38 Wiring Methods

Chapter 38 Wiring Methods

Chapter 39 Power and Lighting Distribution

Chapter 39 Power and Lighting Distribution

Chapter 40 Devices and Luminaires

Chapter 40 Devices and Luminaires

Chapter 41 Appliance Installation

Chapter 41 Appliance Installation

Chapter 42 Swimming Pools

Chapter 42 Swimming Pools

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

Chapter 43 Class 2 Remote-Control, Signaling and Power-Limited Circuits

Chapter 44 Referenced Standards

Chapter 45 HIGH WIND ZONES

Chapter 46 COASTAL AND FLOOD PLAIN CONSTRUCTION STANDARDS

Appendix A Sizing and Capacities of Gas Piping

Appendix B Sizing of Venting Systems Serving Appliances Equipped With Draft Hoods, Category I Appliances, and Appliances Listed for Use With Type B Vents

Appendix C Exit Terminals of Mechanical Draft and Direct-Vent Venting Systems

Appendix D Recommended Procedure for Safety Inspection of an Existing Appliance Installation

Appendix E Manufactured Housing Used as Dwellings

Appendix F Radon Control Methods

Appendix G Swimming Pools, Spas and Hot Tubs

Appendix H Patio Covers

Appendix I Private Sewage Disposal

Appendix J Existing Buildings and Structures

Appendix K Sound Transmission

Appendix L Permit Fees

Appendix M Home Day Care - R-3 Occupancy

Appendix M WOOD DECKS

Appendix N Venting Methods

Appendix N BASIC LOAD ESTIMATING

Appendix O Gray Water Recycling Systems

Appendix O FOAM PLASTIC DIAGRAMS

Appendix P Sizing of Water Piping System

Appendix P DWELLING UNIT FIRE SPRINKLER SYSTEMS

Appendix Q ICC International Residential Code Electrical Provisions/National Electrical Code Crossreference

Appendix Q DISCONTINUOUS FOOTING DETAIL FOR GARAGE OR PORCH WALLS FOUNDATION WALL EXTENSION DETAIL

Appendix M WOOD DECKS

STATE AMENDMENT
This appendix is a North Carolina addition to the 2009 International Residential Code.
(The provisions contained in this appendix are adopted as part of this code.)

Section AM101 GENERAL

STATE AMENDMENT

AM101.1 General

STATE AMENDMENT
A deck is an exposed exterior wood floor structure which may be attached to the structure or freestanding. Roofed porches (open or screened-in) may be constructed using these provisions.

AM101.2 Deck design

STATE AMENDMENT
Computer deck design programs may be accepted by the code enforcement official.

Section AM102 FOOTERS

STATE AMENDMENT

AM102.1 Footers

STATE AMENDMENT
Support post shall be supported by a minimum footing per Figure AM102 and Table AM102.1. Minimum footing depth shall be 12-inches below finished grade per Section R403.1.4. Tributary area is calculated per Figure AM102.1.
FIGURE AM102

Note: Tributary area of shaded section on free standing deck shown is 5' x 6' = 30 sq. ft. Code will require a minimum footer of 8" x 16" per Table AM102.1.
FIGURE AM102.1


TABLE AM102.1
FOOTING TABLEa,b,c
SIZE (inches) TRIBUTARY AREA THICKNESS (inches)
A x A B x C (sq. ft.) Precast Cast-in-Place
8 x 16 8 x 16 36 4 6
12 x 12 12 x 12 40 4 6
16 x 16 70 8 8
16 x 24 100 8
24 x 24 150 8
For SI: 1 inch = 25.4 mm, 1 square foot = 0.0929 m2.
  1. Footing values are based on single floor and roof loads
  2. Support post must rest in center 13 of footer
  3. Top of footer shall be level for full bearing support of post

Section AM103 FLASHING

STATE AMENDMENT

AM103.1 Flashing

STATE AMENDMENT
When attached to a structure, the structure to which attached shall have a treated wood band for the length of the deck, or corrosion-resistant flashing shall be used to prevent moisture from coming in contact with the untreated framing of the structure. Aluminum flashing shall not be used in conjunction with deck construction. The deck band and the structure band shall be constructed in contact with each other except on brick veneer structures and where plywood sheathing is required and properly flashed. Siding shall not be installed between the structure and the deck band. If attached to a brick structure, neither the flashing nor a treated band for brick structure is required. In addition, the treated deckband shall be constructed in contact with the brick veneer. Flashing shall be installed per Figure AM103.

FIGURE AM103

AM104.1 Deck attachment

STATE AMENDMENT
When a deck is supported at the structure by attaching the deck to the structure, the following attachment schedules shall apply for attaching the deck band to the structure.
METHOD FASTENERS 8' MAX
JOIST
SPANa
16' MAX
JOIST
SPANa
1 5⁄8" Hot dipped galv. bolts with nut and washerb
and
12d Common hot dipped galv. nailsc
1 @ 3'-6" o.c.
and
2 @ 8" o.c.
1 @ 1'-8" o.c.
and
3 @ 6" o.c.
OR
2 Self-drilling screw fastenerd 12" o.c staggered 6" o.c staggered
  1. Attachment interpolation between 8 foot and 16 foot joists span is allowed.
  2. Minimum edge distance for bolts is 2½ inches.
  3. Nails must penetrate the supporting structure band a minimum of 1½ inches.
  4. Self-drilling screw fastener shall be an approved screw having a minimum shank diameter of 0.195" and a length long enough to penetrate through the supporting structure band. The structure band shall have a minimum depth of 1⅛". Screw shall have an evaluated allowable shear load for Southern Pine to Southern Pine lumber of 250 pounds and shall have a corrosion resistant finish equivalent to hot dipped galvanized. Minimum edge distance for screws is 1716". A maximum of 12" thick wood structural panel is permitted to be located between the deck ledger and the structure band.
FASTENERS 8' MAX JOIST SPANa 16' MAX JOIST  SPANa
58" Hot dipped galv. bolts with nut and washerb 1@ 2'-4" o.c. 1@ 1'-4" o.c.
  1. Attachment interpolation between 8 foot and 16 foot joist span is allowed.
  2. Minimum edge distance for bolts is 21/2 inches.
If the deck band is supported by a minimum of 12 inch masonry ledge along the foundation wall, 58 inch hot dipped galvanized bolts with washers spaced at 48 inches o.c. may be used for support.
Joist hangers or other means of attachment may be connected to house band and shall be properly flashed.
Girders shall bear directly on support post with post attached at top to prevent lateral displacement or be connected to the side of posts with two 58 inch hot dipped galvanized bolts with nut and washer. Girder spans are per Tables R502.5(1) and (2). Girder support may be installed per Figure AM105 for top mount; Figure AM105.1 for side mount and Figure AM105.2 for split girder detail. Girders may also be cantilevered off ends of support post no more than 1 joist spacing or 16 inches, whichever is greater per Figure AM105.3.

TOP MOUNT/FLUSH
FIGURE AM105

SIDE MOUNT DROPPED GIRDER
FIGURE AM105.1

SPLIT GIRDER DETAIL
FIGURE AM105.2

CANTILEVERED DROPPED GIRDER DETAIL
FIGURE AM105.3
Joists spans shall be based upon Table R502.3.1(2) with 40 lbs per sq. ft. live load and 10 lbs per sq. ft. dead load. Floor joists for exterior decks may be cantilevered per Table R502.3.3 (1).

Section AM107 FLOOR DECKING

STATE AMENDMENT

AM107.1 Floor decking

STATE AMENDMENT
Floor decking shall be No. 2 grade treated Southern Pine or equivalent. The minimum floor decking thickness shall be as follows:

SPACING
DECKING (nominal)
12" o.c 1" S4S
16" o.c. 1" T&G
19.2" o.c. 1¼" S4S
24"-36" o.c. 2" S4S

Section AM108 POST HEIGHT

STATE AMENDMENT

AM108.1 Post height

STATE AMENDMENT
Maximum height of deck support posts as follows:

Post sizea Max. Post Heightb,c
4x4
6x6
8'-0"
20'-0"
  1. This table is based on No. 2 Southern Pine posts.
  2. From top of footing to bottom of girder.
  3. Decks with post heights exceeding these requirements shall be designed by a registered design professional.

Section AM109 DECK BRACING

STATE AMENDMENT

AM109.1 Deck bracing

STATE AMENDMENT
Decks shall be braced to provide lateral stability. The following are acceptable means to provide lateral stability.

AM109.1.1

STATE AMENDMENT
When the deck floor height is less than 4'-0" above finished grade per Figure AM109 and the deck is attached to the structure in accordance with Section AM104, lateral bracing is not required.
FIGURE AM109

AM109.1.2

STATE AMENDMENT
4x4 wood knee braces may be provided on each column in both directions. The knee braces shall attach to each post at a point not less than 13 of the post length from the top of the post, and the braces shall be angled between 45 degrees and 60 degrees from the horizontal. Knee braces shall be bolted to the post and the girder/double band with one 58 inch hot dipped galvanized bolt with nut and washer at both ends of the brace per Figure AM109.1

FIGURE AM109.1

AM109.1.3

STATE AMENDMENT
For freestanding decks without knee braces or diagonal bracing, lateral stability may be provided by embedding the post in accordance with Figure AM109.2 and the following:

POST SIZE MAXIMUM TRIBUTARY AREA MAXIMUM POST HEIGHT EMBEDMENT DEPTH CONCRETE DIAMETER
4x4 48 SF 4'-0" 2'-6" 1'-0"
6x6 120 SF 6'-0" 3'-6" 1'-8"

FIGURE AM109.2

AM109.1.4

STATE AMENDMENT
2x6 diagonal vertical cross bracing may be provided in two perpendicular directions for freestanding decks or parallel to the structure at the exterior column line for attached decks. The 2x6’s shall be attached to the posts with one 58 inch hot dipped galvanized bolt with nut and washer at each end of each bracing member per Figure AM109.3.
FIGURE AM109.3

AM109.1.5

STATE AMENDMENT
For embedment of piles in Coastal Regions, see Chapter 45.

Section AM110 STAIRS

STATE AMENDMENT
Stringer spans shall be no greater than 7 foot span between supports. Spacing between stringers shall be based upon decking material used per AM107.1. Each Stringer shall have minimum 3½ inches between step cut and back of stringer. If used, suspended headers shall shall be attached with 38 inch galvinized bolts with nuts and washers to securely support stringers at the top.

FIGURE AM110
Deck handrails, guards and general construction shall be per Figure AM111.

FIGURE AM111

FIGURE AM112
WALKWAYS OVER DUNES OR BERMS IN OCEAN HAZARD AREAS
For SI: 1 inch = 25.4, 1 foot = 304.8 mm.
*  Posts for walkways over dunes or berms shall be embedded a minimum depth of 4'-0" and post heights shall be limited to 5'-0" above grade for 4 x 4 and 10'-0" above grade for 6 x 6. Walkways or portions of walkways over 4'0" in width shall comply with the requirements of Chapters 45 and 46. Maximum walkway surface height is 30" above grade without guard rails.
**  Walkway stair runs can be greater than 12' without a landing.
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