If you notice that your soffit vents are dirty, don’t wait. You should clean soffit (eave) and other types of attic air intake vents at least every couple of years, if not annually. The best way to clean them is with blasts of compressed air to blow away dust, dirt and any loose insulation that may have fallen into the soffit area.
Attic ventilation is critical to the health of your house. It begins with soffit vents that inhale outside air—necessary to create an airflow that moves warm attic air out the roof vents. Once the air enters the soffit, it usually proceeds through an air chute or some other opening along the underside of the roof into the attic where it helps push warm attic air out the roof vents (See “How Attic Venting Works” below). The plastic air chutes (from home centers and building suppliers) in each rafter space keep the air path clear between the rafters and the roof sheathing.
The benefits of ensuring good attic airflow are fourfold:
- Reduces moisture buildup that prevents mildew growth and rot on your roof’s framing and sheathing
- Reduces cooling costs during hot weather, which can be dramatic if your attic is under-insulated
- Extends shingle life by keeping the roof cooler in hot weather
- Reduces ice dams and the potential damage they cause during snow season.
How Attic Venting Works
With good venting air flows up through the soffit vent and along the underside of the roof into the attic. It mixes with attic air and flows out through roof vents or a ridge vent higher up. This cools the attic in the summer and flushes out moisture in the winter.