What Does the North Carolina Residential Code Require for a Reroof?

The 2018 North Carolina Residential Code applies to most one- and two-family home reroofs in North Carolina in October 2026. The 2024 State Building Code was scheduled for January 1, 2025, but the General Assembly delayed it. The Office of State Fire Marshal explains that under Session Law 2025-2 the 2024 code takes effect 12 months after certain conditions are certified, and the Town of Cary's code page says the 2024 codes will not take effect until some time after March 1, 2027.

Until then, the State Fire Marshal notes that a building owner or agent may request to use the 2024 code as an alternative method of construction. For a reroof, that rarely comes up, but it can matter for wind design, since newer editions can carry updated wind maps.

The North Carolina Residential Code is built on the International Residential Code, published by the International Code Council, and North Carolina amends it. Its roofing chapter, Chapter 9, covers roof assemblies, and a section within it covers reroofing. The rest of this article describes the model code's reroofing rules, which the NC code follows in structure; because the state amends the model text, ask your inspector to confirm the NC wording for your project. Your local inspections department enforces the code and interprets it for your house.

A roof replacement removes all existing roof coverings down to the deck before the new roof goes on. A roof recover, often called a roof-over or layover, installs a new roof covering over an existing one without tearing it off. The code treats them differently.

In the 2018 International Residential Code's reroofing section, R908.3 says roof replacement shall include the removal of existing layers of roof coverings down to the roof deck. A recover is allowed only where the conditions in the code permit it, and the new covering still has to be installed to the code and the manufacturer's instructions.

Replacement has practical advantages beyond code. With the old roof off, the crew can see the deck, replace rotted or damaged sheathing, re-nail the deck where needed and install new underlayment and flashing. A recover hides the deck, adds weight and can make fastening less reliable, because fasteners pass through the old layer.

North Carolina's permit statute also treats them differently. G.S. 160D-1110 lists the addition of roofing, excluding replacement, as work that still needs a permit even under $40,000. Our article on roof permits in NC explains that rule, and metal roof over existing shingles covers roof-overs with metal.

Under the model code's reroofing rules, a roof recover is not permitted when any of these conditions exist:

• The existing roof or roof covering is water-soaked or has deteriorated to the point that it is not adequate as a base for additional roofing.
• The existing roof covering is slate, clay, cement or asbestos-cement tile.
• The existing roof has two or more applications of any type of roof covering.

In practice, that means a house with a single layer of sound asphalt shingles may be eligible for a roof-over, while a house with two layers already, a soft or rotted deck, or a slate or tile roof needs a tear-off.

The model code includes a few narrow exceptions, so ask your roofer which provision they are relying on and get it in writing. A roofer recommending a roof-over should be able to explain why the existing roof qualifies, how the new roof will be fastened through it and what happens to the flashing.

The model code requires flashing to be reconstructed in accordance with approved manufacturer's installation instructions on a reroof, and it limits what can be reused. Section R908.6 says flashings shall be reconstructed per approved manufacturer's instructions, and metal flashing to which bituminous materials will be adhered must be primed first.

For reuse, the model code allows existing slate, clay or cement tile to be reinstalled, but damaged, cracked or broken slate or tile may not be. Existing flashings, edgings, outlets, vents or similar devices that are part of the assembly must be replaced when they are rusted, damaged or deteriorated, and aggregate surfacing may not be reinstalled.

Flashing is where many leaks start, so this matters as much as the roof covering. On a reroof, expect new step flashing along sidewalls, new counterflashing or a proper detail at chimneys, new pipe boots and new edge metal unless the existing pieces are in excellent condition and compatible with the new roof. Reusing old flashing to save time is a common shortcut that leads to leaks a few years later. Ask the contractor to list each flashing location in the contract and what will be done there. Our article on roof leaks after a thunderstorm shows where flashing problems tend to show up.

The roof covering on a reroof must be suitable for the design wind speed at the house, and North Carolina's code includes its own wind provisions. The state's amendment record shows it replacing the model code's wind map with a North Carolina version and adding high-wind and coastal construction provisions, and design wind speeds rise toward the coast.

For a reroof, wind requirements show up in product choice and installation details: shingles with a wind classification suited to the location, metal panels tested to the right uplift pressure, fastening patterns at corners and edges, and edge metal attached to resist peeling. On the coast, insurers may also look for features like a sealed deck under mitigation and FORTIFIED programs.

A reroof is also the one moment the deck is exposed, which makes it the time to re-nail sheathing to a stronger pattern if needed. IBHS's FORTIFIED Roof standard uses ring-shank nails in an enhanced pattern and a sealed deck, and its testing found that switching from smooth nails to 8d ring-shank nails at tighter spacing can double the deck's uplift resistance. See NC coastal wind zones and FORTIFIED roofs.

A reroof contract should spell out how the job will meet code, not just promise that it will. Specific language protects you if something is missed and gives you a checklist for the final walk-through.

Look for these items:

• Whether the job is a full tear-off to the deck or a recover, and why a recover qualifies if proposed.
• How damaged decking will be identified, replaced and priced.
• The underlayment product and how it will be installed, including at valleys and eaves.
• Flashing at each wall, chimney, valley and penetration, and whether it is new.
• Edge metal, starter and ridge details, and fastening patterns for the location's wind requirements.
• Ventilation: intake and exhaust, and whether existing vents are reused.
• Who determines whether a permit is needed, who obtains it and who schedules inspections.
• Product names, colors and the warranties that apply.

For an Interlock aluminum roof, Metal Roof NC, an authorized Interlock dealer, includes these details in a project-specific estimate before work begins. Interlock profiles need a minimum 3/12 slope. Metal Roof NC requires tear-off for cedar shingles and shakes, concrete and clay tile and natural slate, and roofs over a single layer of asphalt only if an inspection finds it suitable and the local code allows. Our roofing contract checklist and roof replacement page cover the rest.