Attic Ventilation Soffit Ridge Balance

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

Attic ventilation soffit ridge balance.

1 being out of balance. Outside air enters the attic space through soffit or eave vents rises through the attic space as it warms and exits through vents that are positioned at or near the top. If the attic ventilation system is not a balanced combination of intake vents installed in the soffit under eave or at the roof s bottom edge and exhaust vents installed at or near the roof s peak the attic ventilation system will not be efficient and effective. Continuous ventilation systems with ridge and soffit vents keep attics dry.

The soffit vents allow convective air movement from the soffits of the residence to the ridge vent. Attic ventilation soffit intake to ridge outlet air flow or square inches ratio. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Intake vents such as soffits are placed lower on the roof usually under the eaves.

In addition insulation baffles must be installed at the point where the attic floor meets the roofline to prevent the attic insulation from migrating into the cavities and restricting the airflow from the soffit vents. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. Moisture in the attic can cause mold to grow and the wood can rot so air circulation is very important. Click to enlarge any image.

218 4 pieces 389 3 pieces 829 2 pieces. Adding under roof ventilation is usually a great idea but if the relative sizes of the intake and outlet vents are not proper the building will suffer increased heat loss and thus an unnecessarily high home heating bill. The balance of the required ventilation provided shall be located in the bottom one third of the attic space. Soffit vents are one of the most popular intake vent styles.

Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. Continuous or individual soffits. Learn how to plan a continuous ridge and soffit ventilation system for your attic and how to install soffit vents and other attic venting systems. They are easy to install under the roof s overhang which is known as the soffit are generally hidden from sight and provide excellent protection from weather outdoor debris and pests while still allowing air to flow into the attic.

Where the location of wall or roof framing members conflicts.