CODES

ADOPTS WITH AMENDMENTS:

International Residential Code 2015 (IRC 2015)

Part I ‒ Administrative

Chapter 1 Scope and Administration

Part II ‒ Definitions

Chapter 2 Definitions

Part III ‒ Building Planning and Construction

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

Part IV ‒ Energy Conservation

Chapter 11 [RE] Energy Efficiency

Part V ‒ Mechanical

Chapter 12 Mechanical Administration

Chapter 13 General Mechanical System Requirements

Chapter 14 Heating and Cooling Equipment and Appliances

Chapter 15 Exhaust Systems

Chapter 16 Duct Systems

Chapter 17 Combustion Air

Chapter 18 Chimneys and Vents

Chapter 19 Special Appliances, Equipment and Systems

Chapter 20 Boilers and Water Heaters

Chapter 21 Hydronic Piping

Chapter 22 Special Fuel oil Piping and Storage Systems

Chapter 23 Solar Thermal Energy Systems

Part VI ‒ Fuel Gas

Chapter 24 Fuel Gas

Part VII ‒ Plumbing

Chapter 25 Plumbing Administration

Chapter 26 General Plumbing Requirements

Chapter 27 Plumbing Fixtures

Chapter 28 Water Heaters

Chapter 29 Water Supply and Distribution

Chapter 30 Sanitary Drainage

Chapter 31 Vents

Chapter 32 Traps

Chapter 33 Storm Drainage

Part VIII ‒ Electrical

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

Part IX ‒ Referenced Standards

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 E (E-1 THROUGH E-4)
RESIDENTIAL REQUIREMENTS FOR ENERGY CONSERVATION

Appendix F Radon Control Methods

Appendix G Piping Standards for Various Applications

Appendix H Patio Covers

Appendix I Private Sewage Disposal

Appendix J Existing Buildings and Structures

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 O Automatic Vehicular Gates

Appendix O FOAM PLASTIC DIAGRAMS

Appendix P Sizing of Water Piping System

Appendix Q Reserved

Appendix Q DISCONTINUOUS FOOTINGS

Appendix R Light Straw-Clay Construction

Appendix S Strawbale Construction

Appendix T Recommended Procedure for Worst-Case Testing of Atmospheric Venting Systems Under N1102.4 or N1105 Conditions ≤ 5ACH50

Appendix U SOLAR-READY PROVISIONS—DETACHED ONE- AND TWO-FAMILY DWELLINGS, MULTIPLE SINGLE- FAMILY DWELLINGS (TOWNHOUSES)

Appendix V SWIMMING POOLS, SPAS AND HOT TUBS

Appendix W BASIC LOAD ESTIMATING

Chapter 26 General Plumbing Requirements

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
User note: Code change proposals to this chapter will be considered by the IRC ‒ Plumbing and Mechanical Code Development Committee during the 2015 (Group A) Code Development Cycle. The text of this chapter is extracted from the 2018 edition of the North Carolina Plumbing Code and has been modified where necessary to conform to the scope of application of the North Carolina Residential Code for One- and Two-Family Dwellings. The section numbers appearing in parentheses after each section number are the section numbers of the corresponding text in the North Carolina Plumbing Code.

P2601.1 (301.1) Scope

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
The provisions of this chapter shall govern the installation of plumbing not specifically covered in other chapters applicable to plumbing systems. The installation of plumbing, appliances, equipment and systems not addressed by this code shall comply with the applicable provisions of the International Plumbing Code.

P2601.2 (301.3) Connections to Drainage System

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Plumbing fixtures, drains, appurtenances and appliances used to receive or discharge liquid wastes or sewage shall be directly connected to the sanitary drainage system of the building or premises, in accordance with the requirements of this code. This section shall not be construed to prevent indirect waste connections where required by the code.

Exception: Bathtubs, showers, lavatories, clothes washers and laundry trays shall not be required to discharge to the sanitary drainage system where such fixtures discharge to systems complying with Sections P2910 and P2911. All drain, waste and vent piping associated with gray water or rain water recycling systems shall be installed in compliance with this code.
In flood hazard areas as established by Table R301.2(1), plumbing fixtures, drains, and appliances shall be located or installed in accordance with Section R322.1.6.

P2602.1 General

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
The water-distribution and drainage system of any building or premises where plumbing fixtures are installed shall be connected to a public water supply or sewer system, respectively, if available. Where either a public water-supply or sewer system, or both, are not available, or connection to them is not feasible, an individual water supply or individual (private) sewage-disposal system, or both, shall be provided.

Exception: All drain, waste and vent piping associated with gray water or rain water recycling systems shall be installed in compliance with this code.

P2602.2 (309.2) Flood-Resistant Installation

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
In flood hazard areas as established by Table R301.2(1):
  1. Water supply systems shall be designed and constructed to prevent infiltration of floodwaters.
  2. Pipes for sewage disposal systems shall be designed and constructed to prevent infiltration of floodwaters into the systems and discharges from the systems into floodwaters.
In the process of installing or repairing any part of a plumbing and drainage installation, the finished floors, walls, ceilings, tile work or any other part of the building or premises that must be changed or replaced shall be left in a safe structural condition in accordance with the requirements of the building portion of this code.
Wood-framed structural members shall not be drilled, notched or altered in any manner except as provided in Sections R502.8, R602.6, R802.7 and R802.7.1. Holes in load-bearing members of cold-formed steel light-frame construction shall be made only in accordance with Sections R505.2.6, R603.2.6 and R804.2.6. In accordance with the provisions in Sections R505.3.5, R603.3.3 and R804.3.4, cutting and notching of flanges and lips of load-bearing members of cold-formed steel light-frame construction shall be prohibited. Structural insulated panels (SIPs) shall be drilled and notched or altered in accordance with the provisions of Section R613.7.
In concealed locations, where piping, other than cast-iron or galvanized steel, is installed through holes or notches in studs, joists, rafters or similar members less than 11/4 inches (31.8 mm) from the nearest edge of the member, the pipe shall be protected by steel shield plates. Such shield plates shall have a thickness of not less than 0.0575 inch (1.463 mm) (No. 16 Gage). Such plates shall cover the area of the pipe where the member is notched or bored, and shall extend not less than 2 inches (51 mm) above sole plates and below top plates.

P2603.3 (305.1) Protection Against Corrosion

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Metallic piping, except for cast iron, ductile iron and galvanized steel, shall not be placed in direct contact with steel framing members, concrete or masonry. Metallic piping shall not be placed in direct contact with corrosive soil. Where sheathing is used to prevent direct contact, the sheathing material thickness shall be not less than 0.008 inch (8 mil) (0.203 mm) and shall be made of plastic. Where sheathing protects piping that penetrates concrete or masonry walls or floors, the sheathing shall be installed in a manner that allows movement of the piping within the sheathing. Pipes passing through concrete or cinder walls and floors or other corrosive material shall be protected against external corrosion by a protective sheathing or wrapping or other means that will withstand any reaction from the lime and acid of concrete, cinder or other corrosive material. Sheathing or wrapping shall allow for movement including expansion and contraction of piping. The wall thickness of the material shall be not less than 0.025 inch (0.64 mm).

P2603.4 (305.3) Pipes through or under footings or foundation walls

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
A pipe that passes through a foundation wall shall be provided with a relieving arch, or a pipe sleeve shall be built into the foundation wall. The sleeve shall be two pipe sizes greater than the pipe passing through the wall. Any pipe that passes within 12 inches (305 mm) of the bottom of the footing or through a foundation wall shall be provided with a relieving arch or a pipe sleeve. Pipe sleeves for foundation walls shall be built into the foundation wall. The sleeve shall be two pipe sizes greater than the pipe passing through the wall. Piping shall not be run under pier footings (refer to Section P2604). Annular spaces between sleeves and pipes shall be filled or tightly sealed in an approved manner. Annular spaces between sleeves and pipes in fire-resistance-rated assemblies shall be filled or tightly sealed in accordance with the North Carolina Building Code. Only sleeves through foundation or exterior building walls shall be sealed on both sides.

P2603.5 Freezing

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
In localities having a winter design temperature of 32°F (0°C) or lower as shown in Table R301.2(1) of this code, a water, soil or waste pipe shall not be installed outside of a building, in exterior walls, in attics or crawl spaces, or in any other place subjected to freezing temperature unless adequate provision is made to protect it from freezing by insulation or heat or both. Water service pipe shall be installed not less than 12 inches (305 mm) deep and not less than 6 inches (152 mm) below the frost line. Water pipes installed in a wall exposed to the exterior shall be located on the heated side of the wall insulation. In other cases, water, soil and waste pipes shall not be installed outside of a building, in unconditioned attics, unconditioned utility rooms or in any other place subjected to freezing temperatures unless adequate provision is made to protect such pipes from freezing by a minimum of R-6.5 insulation determined at 75°F (24°C) in accordance with ASTM C177 or heat or both.

     Exterior water supply system piping shall be installed not less than 6 inches (152 mm) below the frost line and not less than 12 inches (305 mm) below grade.

Note: These provisions are minimum requirements, which have been found suitable for normal weather conditions. Abnormally low temperatures for extended periods may require additional provisions to prevent freezing.

P2603.5.1 Sewer Depth

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Building sewers that connect to private sewage disposal systems shall be ainstalled not less than [NUMBER]3 inches (76.2 mm) below finished grade at the point of septic tank connection. Building sewers shall be not less than [NUMBER]3 inches (76.2 mm) below grade.

P2604.1 (306.2) Trenching and Bedding

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Where trenches are excavated such that the bottom of the trench forms the bed for the pipe, solid and continuous load-bearing support shall be provided between joints. Where over-excavated, the trench shall be backfilled to the proper grade with compacted earth, sand, fine gravel or similar granular material. Piping shall not be supported on rocks or blocks at any point. Rocky or unstable soil shall be over-excavated by two or more pipe diameters and brought to the proper grade with suitable compacted granular material. Bell holes, hub holes and coupling holes shall be provided at points where the pipe is joined. Such pipe shall not be supported on blocks to grade. In instances where the materials manufacturer’s installation instructions are more restrictive than those prescribed by the code, the material shall be installed in accordance with the more restrictive requirement.

P2604.1.1 Over-excavation

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Where trenches are excavated below the installation level of the pipe such that the bottom of the trench does not form the bed for the pipe, the trench shall be backfilled to the installation level of the bottom of the pipe with sand or fine gravel placed in layers not greater than 6 inches (152 mm) in depth and such backfill shall be compacted after each placement.

P2604.1.2 Rock removal

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Where rock is encountered in trenching, the rock shall be removed to not less than 3 inches (76 mm) below the installation level of the bottom of the pipe, and the trench shall be backfilled to the installation level of the bottom of the pipe with sand tamped in place so as to provide uniform load-bearing support for the pipe between joints. The pipe, including the joints, shall not rest on rock at any point.

P2604.1.3 Soft load-bearing materials

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
If soft materials of poor load-bearing quality are found at the bottom of the trench, stabilization shall be achieved by over excavating not less than two pipe diameters and backfilling to the installation level of the bottom of the pipe with fine gravel, crushed stone or a concrete foundation. The concrete foundation shall be bedded with sand tamped into place to provide uniform load-bearing support for the pipe between joints.
Where the water service piping and building sewer piping is installed in same trench, the installation shall be in accordance with Section P2906.4.1.
Backfill shall be free from discarded construction material and debris. Backfill shall be free from rocks, broken concrete and frozen chunks until the pipe is covered by not less than 12 inches (305 mm) of tamped earth. Backfill shall be placed evenly on both sides of the pipe and tamped to retain proper alignment. Loose earth shall be carefully placed in the trench in 6-inch (152 mm) layers and tamped in place.
Trenching installed parallel to footings and walls shall not extend into the bearing plane of a footing or wall. The upper boundary of the bearing plane is a line that extends downward, at an angle of 45 degrees from horizontal, from the outside bottom edge of the footing or wall.
Piping shall be supported in accordance with the following:

1. Piping shall be supported to ensure alignment and prevent sagging, and allow movement associated with the expansion and contraction of the piping system.

2. Piping in the ground shall be laid on a firm bed for its entire length, except where support is otherwise provided.

3. Hangers and anchors shall be of sufficient strength to maintain their proportional share of the weight of pipe and contents and of sufficient width to prevent distortion to the pipe. Hangers and strapping shall be of approved material that will not promote galvanic action. Rigid support sway bracing shall be provided at changes in direction greater than 45 degrees (0.79 rad) for pipe sizes 4 inches (102 mm) and larger.

4. Piping shall be supported at distances not to exceed those indicated in Table P2605.1.

TABLE P2605.1 PIPING SUPPORT

PIPING MATERIAL MAXIMUM HORIZONTAL
SPACING (feet)
MAXIMUM VERTICAL
SPACING (feet)
ABS pipe 4 10b
Aluminum tubing 10 15
Cast-iron pipe 5a 15
Copper or copper alloy pipe 12 10
Copper or copper alloy tubing (11/4 inches in diameter and smaller) 6 10
Copper or copper alloy tubing (11/2 inches in diameter and larger) 10 10
Cross-linked polyethylene (PEX) pipe, 1 inch and smaller 2.67 (32 inches) 10b
Cross-linked polyethylene (PEX) pipe, 11/4 inch and larger 4 10b
Cross-linked polyethylene/aluminum/cross-linked polyethylene (PEX-AL-PEX) pipe 2.67 (32 inches) 4b
CPVC pipe or tubing (1 inch in diameter and smaller) 3 10b
CPVC pipe or tubing (11/4 inches in diameter and larger) 4 10b
Lead pipe Continuous 4
PB pipe or tubing 2.67 (32 inches) 4
Polyethylene of raised temperature (PE-RT) pipe, 1 inch and smaller 2.67 (32 inches) 10b
Polyethylene of raised temperature (PE-RT) pipe, 11/4 inch and larger 4 10b
Polypropylene (PP) pipe or tubing (1 inch and smaller) 2.67 (32 inches) 10b
Polypropylene (PP) pipe or tubing (11/4 inches and larger) 4 10b
PVC pipe 4 10b
Stainless steel drainage systems 10 10b
Steel pipe 12 15

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a. The maximum horizontal spacing of cast-iron pipe hangers shall be increased to 10 feet where 10-foot lengths of pipe are installed.
b. For sizes 2 inches and smaller, a guide shall be installed midway between required vertical supports. Such guides shall prevent pipe movement in a direction perpendicular to the axis of the pipe.

P2606.1 (315.1) Sealing of Annular Spaces

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
The annular space between the outside of a pipe and the inside of a pipe sleeve or between the outside of a pipe and an opening in a building envelope wall, floor, or ceiling assembly penetrated by a pipe shall be sealed with caulking material or foam sealant or closed with a gasketing system. The caulking material, foam sealant or gasketing system shall be designed for the conditions at the penetration location and shall be compatible with the pipe, sleeve and building materials in contact with the sealing materials. Annular spaces created by pipes penetrating fire-resistance-rated assemblies or membranes of such assemblies shall be sealed or closed in accordance with the building portion of this code.

P2607.1 (305.5) Pipes Penetrating Roofs

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Where a pipe penetrates a roof, a flashing of lead, copper, galvanized steel or an approved elastomeric material shall be installed in manner that prevents water entry into the building. Counterflashing into the opening of pipe serving as a vent terminal shall not reduce the required internal cross-sectional area of the vent pipe to less than the internal cross-sectional area of one pipe size smaller. Joints at the roof and around vent pipes shall be made watertight by the use of lead, copper, galvanized steel, aluminum, plastic or other approved flashings or flashing material.

P2607.2 (305.5) Pipes Penetrating Exterior Walls

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Where a pipe penetrates an exterior wall, a waterproof seal shall be made on the exterior of the wall by one of the following methods:
  1. A waterproof sealant applied at the joint between the wall and the pipe.
  2. A flashing of an approved elastomeric material.
Valves, pipes and fittings shall be installed in correct relationship to the direction of the flow. Burred ends shall be reamed to the full bore of the pipe.
Each length of pipe and each pipe fitting, trap, fixture, material and device utilized in a plumbing system shall bear the identification of the manufacturer and any markings required by the applicable referenced standards. Nipples created from the cutting and threading of approved pipe shall not be required to be identified.

Exception: Where the manufacturer identification cannot be marked on pipe fittings and pipe nipples because of the small size of such fittings, the identification shall be printed on the item packaging or on documentation provided with the item.
Materials used shall be installed in strict accordance with the standards under which the materials are accepted and approved. In the absence of such installation procedures, the manufacturer's instructions shall be followed. Where the requirements of referenced standards or manufacturer's instructions do not conform to the minimum provisions of this code, the provisions of this code shall apply.

P2609.2.1 (402.2) Materials for specialty fixtures

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Materials for specialty fixtures not otherwise covered in this code shall be of stainless steel, soapstone, chemical stoneware or plastic, or shall be lined with lead, copper-base alloy, nickel-copper alloy, corrosion-resistant steel or other material especially suited to the application for which the fixture is intended.

P2609.2.2 (402.3) Sheet copper

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Sheet copper for general applications shall conform to ASTM B152 and shall not weigh less than 12 ounces per square foot (3.7 kg/m2).

P2609.2.3 (402.4) Sheet lead

AMENDMENT
This section has been amended at the state or city level. Amendments are shown in green text.
Sheet lead for pans shall not weigh less than 4 pounds per square foot (19.5 kg/m2) and shall be coated with an asphalt paint or other approved coating.
Plastic pipe, fittings and components shall be third-party certified as conforming to NSF 14.
Plumbing products and materials required by the code to be in compliance with a referenced standard shall be listed by a third-party certification agency as complying with the referenced standards. Products and materials shall be identified in accordance with Section P2609.1.
Water service pipes, water distribution pipes and the necessary connecting pipes, fittings, control valves, faucets and appurtenances used to dispense water intended for human ingestion shall be evaluated and listed as conforming to the requirements of NSF 61.
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