Proper ventilation is critical to extending the life of your roof. Air movement will expel moist air, prevent heat buildup, and reduce ice dams in colder climates. An attic that is poorly vented may significantly increase the heating and cooling costs for a home.
Ventilation requires intake and exhaust components, and these components need to be balanced. If you have too much intake or exhaust it may actually reduce the effectiveness of the ventilation. If the system is out of balance, it’s better to have too much intake than exhaust.
Ideally, the amount of ventilation is matched to calculation to the volume of the area to be ventilated.
Attic Ventilation Systems, Part 1 – InterNACHI – Ventilation Purpose
Attic Ventilation Systems, Part 2 – InterNACHI – Passive Vents
Attic Ventilation Systems, Part 3 – InterNACHI – Passive Vents (cont’d)
Intake ventilation is usually not modified during a roof repair. Soffit vents, the most widely-used intake ventilation system, are mounted under the eaves of a home. These vents may need to be replaced if the roof has leaked and damaged the area where the soffit is mounted. Soffit vents can be individual vents (as pictured) or continuous. Visit the LOMANCO site on intake ventilation for more images of soffit ventilation.
Typically, roof exhaust ventilation is replaced with the identical type during a re-roof. There are several types of exhaust a home may have, including static vents, non-power vents, ridge vents, turbine vents, and powered vents.
Static vents are exactly what they sound like: a non-moving cover over a vent hole in the roof. They come in different sizes and colors. SEI Roofing typically uses Lomanco vents, and the Lomanco 750 is a static vent:
Turbine vents, such as the WhirlyBird by Lomanco, are vents that spin when wind blows over them. They can move a higher volume of air than a static vent and do not require electrical power. This video will demonstrate a WhirlyBird in action:
Ridge vents provide a discreet, aesthetically-appealing form for ventilation. These are vent strips that are mounted on the ridge of a home and then covered with the same style of shingles as the roof. As a result, the ventilation system is essentially hideen when looking at the home from ground level, as opposed to static or spinning vent alternatives.
SEI Roofing typically uses GAF’s Cobra Ridge Vents,. The first video below is about the GAF product. The second video is a demonstration by Lomanco of ridge vents in action.
Power vents can be used when you really need to move a large value of air. Because they’re powered, they will need to be wired to the house. There is a thermostat that will automatically turn the vent on and off. However, these thermostats can get stuck and result in a vent that is continually running. This will ultimately burn out the motor and use excess electricity.
Solar-powered vents are powered vents that do not need to be wired to a house. SEI Roofing typically will use the Solatube by Solar Star. By design, this vent runs continuously until it depletes the solar energy it has generated. There is an accessory thermostat that can turn the vent on at a certain temperature. Here is an installation video of the Solatube: