What are the roof ventilation code requirements in Georgia?
Short answer. Georgia's mandatory residential code is the 2024 International Residential Code with Georgia amendments, effective January 1, 2026, and its Section R806 requires vented attics to have net free vent area of 1/150 of the attic floor, or 1/300 with balanced high and low vents. Cities and counties enforce it through permits, so the inspector who checks your project is local.
How code works in Georgia
The Georgia Department of Community Affairs adopts the statewide minimum construction codes, including the residential code, and local governments enforce them. Some cities and counties add local amendments or have their own permit rules for roof replacements. New homes and additions get framing and insulation inspections, which is when ventilation is most likely to be checked.
What applies when you reroof
- Permits: many Georgia jurisdictions require a permit for a full roof replacement, and some do not. Requirements vary.
- Ventilation on a reroof: reroof inspections usually focus on the roof covering, underlayment and flashing. Whether an inspector checks the vent math varies by jurisdiction.
- Shingle warranties: manufacturers expect code compliant ventilation whether or not a permit was pulled, so a replacement is the time to correct it.
The key code items
- Net free area of 1/150, or 1/300 when 40 to 50 percent of it is high exhaust within 3 feet of the ridge.
- Vent openings between 1/16 and 1/4 inch, or screened to that range.
- At least 1 inch of air space between insulation and sheathing at eave vents.
- Unvented attics only with insulation meeting the unvented attic section.
- Mechanical exhaust discharged outdoors, not into attics, soffits or ridge vents.
Ask your local building department which edition and amendments apply on your permit date. Read roofing permits in Georgia and roofing warranties explained.