Roof ventilation is an important part of any roofing system. Without proper roof vents, moisture can build up. In the worst cases, this may lead to the decay of not only the roof, but of other parts of the house as well. Keep reading to learn more about venting the roof on your home.

Why Roof Ventilation is Necessary

Properly venting the roof of a house will allow it to breathe, preventing the development of mold, mildew or other fungi that may lead to rot. Without sufficient roof ventilation, a home’s air conditioning unit will need to work harder to cool the structure, costing more in energy. Such a situation can be easily solved by installing additional roof vents.

Types of Roof Vents and Where to Install

You may find a roof vent in a wide variety of different types, including:

• Cupola roof vents
• Gable roof vents
• Power roof vents
• Soffit/cornice roof vents
• Starter roof vents
• Static roof vents.

When venting a roof, you’ll find that a roof vent will come in one of two basic types: an intake or exhaust roof vent. For each intake roof vent, you should also install an exhaust vent.

There are also active or passive roof vents. An active roof vent requires a power source. Passive roof ventilation, however, depends on natural air flow, such as the wind or air rising naturally through the structure.

Ridge vent panels on the ridge of the roof allow air to enter and exit the attic. Turbine roof vents stand up on the ridge of the roof as well, spinning in the wind and pulling air out of the attic.

Don’t forget about venting the roof along the eaves, to allow for the free flow of air throughout the roof. Otherwise, the roof ventilation will only be partially complete.

How Many Roof Vents?

The number of roof vents to install is easy enough to figure. By measuring attic space in a house and including the garage area, you can determine how many roof vents a house should have. For every 300 square feet, the house should have one square foot of roof ventilation. For instance, for a 2,400 square foot home, there should be eight square feet dedicated to roof vents.

Installation and Venting a Roof

Ridge roof vents can be installed along with another roofing job or on their own, and here are some basics on roof ventilation:

• Measure and cut a slot for the vent, careful not to damage the rafters underneath when venting a roof.
• Add roofing material up to the hole, keeping venting material taut.
• Nail venting every 12 inches, ensuring that it penetrates the roofing sheath.
• Cut away the underside of the roof vent to make sure it seals against the roof.
• Cut ridge caps so they wrap around ridge roof vents.
• Drive roofing nails through sheathing so that they are flush.