do i leave air gap in attic roof for insulation?
The best way to set up an attic is to put a vapor barrier under the rafters (before nailing on the gyproc), then put the insulation (fibreglas batts) between the rafters to full depth (10 or 12 inches). Soffit vents are installed under the eaves at the sides of the roof, and gable vents are placed near the peak of the roof at the ends. This allows for airflow resulting from convection, particularly important in the summer months to remove heat buildup in the attic. If the insulation is adequate, it will not only isolate this heat buildup from the inside of the house in summer, but will prevent heat loss to the attic in winter. (The airflow in winter will be minimal, but will remove any moisture/condensation that might collect otherwise.)
