Fig. 2. Cross section of attic showing attic ventilation paths.

Note:

For any of the radiant barrier locations (and for attics without radiant barriers), ideal venting would provide equal areas on intake (soffit) and exhaust (gable or ridge) vents. For proper air flow, with a roof-mounted radiant barrier, a gap of approzimately 3 inches should be left between tha radiant barrier and the insulation, and a gap of at least 6 inches should be left near the ridge. Both of these gaps should be left for attics with either ridge or gable venting.