CHAPTER 8 – ROOF-CEILING ASSEMBLIES
R806.1 Ventilation required. Enclosed attics and enclosed rafter spaces formed where ceilings are applied directly to the underside of roof rafters shall have cross ventilation for each separate space by ventilating openings protected against the entrance of rain or snow. Ventilating openings shall be provided with corrosion-resistant wire mesh, with 1/8-inch minimum to 1/4-inch maximum openings.
Exception: Rafter spaces filled completely with sprayed-in foam insulation complying with Section N1101.3.1.1 of this code.