Roof, Soffit, and Gable Vents
Both roof and soffit vents are needed!
Without soffit vents the hot air can’t get out.
Hot, moist air rises and escapes through rooftop exhaust vents. Cool air is drawn in from the soffit vents. Both intake and exhaust vents are needed. Without soffit vents the hot air can’t get out; it is like sucking on a pop bottle. These vents should be equally spaced around the attic area to avoid “hot spots”. Care must be taken to be sure that the soffit vents are not obstructed by insulation. Insulation baffles can actually obstruct airflow if they are not installed properly.
Roof Vents come in several styles and sizes.
RV51 Roof Vents are installed along the ridge of the roof. They have an insect screen and have 51 square inches of net-free area. They are usually available in black, brown, gray and galvanized. Steel vents stand up best to hail and other weather.
Slantback roof vents are another option. Instead of an insect screen, it has closely spaced louver openings.
B144 Roof Vents are larger, round vents. They also have an insect screen and have 144 square inches of net-free area. They are available in weathered wood and brown and are made of steel.
Ridge vent is installed along the ridge, usually underneath the ridge shingles. A gap is cut through the roof sheathing along the ridge and then the ridge vent is installed.
Several designs are available. Roll ridge vent is the least expensive but does not work as well. Baffled ridge vents direct the wind up and over the ridge to provide negative pressure and pull the hot air out of the attic. They also offer more protection from wind driven rain and snow.
Turbine Vents have a rotating top that is turned by the wind or by the hot air flowing up turbine through it. If the wind is blowing the spinning action of the blades can help pull hot air out of the attic. However, they do have a moving part that will not last as long as the rest of the roof. And they need to spin or rain and snow can come in. Appearancewise they are best suited for barns.
O'Hagin Low Profile Vents are very weathertight and look great. They can be installed on north and west facing slopes and can be installed low on the roof as intake vents.
Gable Vents are placed at the ends of the attics. They can function as either intake or exhaust vents depending on the direction of the wind. They will not work as exhaust vents without soffit vents. They can be square, rectangular, triangle shaped, or round. Gable vents tend to short circuit the attic ventilation. For most efficient ventilation, gable vents should be sealed in favor of only roof and soffit vents.