Attic Cross Ventilation

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Attic cross ventilation.

The insulation will resist heat transfer into the house. You can also contact your local municipality to check on building code in your area. If the attic is insulated with fiberglass batts just pull back any that are blocking the flow of air. Intake vents located at the lowest part of the roof under the eaves allow cool.

If there s blown in insulation like ours rake back the fluffy stuff with a 3 or 4 ft long 1 x 6 or use a garden rake or hoe. The soffit vents are now installed but you still need to make sure there s no insulation blocking the new vents. 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. Proper insulation and air sealing also keeps attics cold in winter by blocking the entry of heat and moist air from below.

In other words the entire vent opening doesn t count as vented space. That said air resistance and interference such as vent grates reduces the area of true ventilation. In the summer natural air flow in a well vented attic moves super heated air out of the attic protecting roof shingles and removing moisture.