What are the code requirements for soffit vents?
Short answer. The residential code has no separate soffit vent section, but its attic rules shape them: intake has to supply its share of the required net free area, sit low at the eaves, have openings or screening between 1/16 and 1/4 inch, and keep at least a 1 inch air space above the insulation at the vent. Local amendments and the shingle manufacturer's instructions can add more.
What the rules mean for intake
- Share of the total: under the 1/300 option, 40 to 50 percent of the required vent area is high, within 3 feet of the ridge, and the balance is low at the eaves. In practice intake ends up at half or a bit more of the total.
- Net free area, not size: the rated open area on the vent counts, not its outside dimensions. A 16 by 8 inch louvered vent has far less than 128 square inches of open area.
- Openings: no smaller than 1/16 inch and no larger than 1/4 inch, or covered with screening, hardware cloth or perforated material in that range.
- Air channel: insulation must leave at least 1 inch of space to the roof sheathing at the vent. Baffles, also called rafter vents, hold that space open.
- Weather protection: vents have to keep out rain and snow, which is one reason soffit vents face downward.
What the code does not say
It does not set a spacing between soffit vents or demand one in every rafter bay, and it does not prefer continuous strips over individual vents. Good practice is to spread intake evenly along every eave so each bay gets air rather than bunching it in one spot.
Where it gets enforced
Georgia has used the 2024 IRC with state amendments since January 1, 2026, and city and county inspectors check ventilation mostly on new construction and major remodels. On a reroof the manufacturer's installation instructions often matter more, because inadequate intake can affect warranty coverage. See roof ventilation basics and roofing permits in Georgia.