Vent Attic With Blocking Vents

The soffit vents are now installed but you still need to make sure there s no insulation blocking the new vents.

Vent attic with blocking vents.

Attic ventilation is a two part process. Diameters are ideal if you have eaves but no soffits. If the attic is insulated with fiberglass batts just pull back any that are blocking the flow of air. These vents available in 2 3 and 4 in.

The photograph at left shows severe mold on the underside of roof sheathing in a 1920 s cape cod attic where there was no under roof ventilation. Blocked soffit vents invites attic or roof cavity moisture condensation mold the photograph at page top shows an attic whose intake venting is blocked by fiberglass insulation. Install them by cutting holes into the blocking between the exposed rafter tails and pressing the vents into the holes. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

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. Available at roofing supply stores and well stocked home centers. Yet many attics with ventilation far superior to the code requirements suffer from mold issues. The minimum recommended attic ventilation is 1 5 of your attic floor space.

Make sure the airflow has a clear pathway through the insulation. First air enters through the soffit vents. Nope venting an attic is actually pretty hard here s how ventilation is supposed to work.