It is important to have ventilation in the attic so any heat lost from the interior of the home is drawn up and out of the attic. Adequate attic ventilation will help the roof deck stay cool in the warm months, lower your cooling costs and extend the life of your new roof. Another benefit of having your attic ventilated is that it allows for moisture that rises into the attic from things such as bathing, cooking and laundry to escape. Unchecked moisture can promote mold, mildew and wood rot.

There are two common ways to ensure that excess moisture or heat can escape to the outside. One way is through a natural or static ventilation system. The other way is by a power or mechanical ventilation system. A power ventilator is an electric powered fan installed on the roof or gable that runs by a thermostat or humidistat when the attic needs ventilation. Natural or static ventilation systems consist of simple vents or covered openings in your attic. These are typically ridge vents, gable, eave or roof vents.

A properly designed ventilation system must have both intake vents in the soffit or eaves, and exhaust ventilation high in the attic at or near the ridge. Typically cooler, dryer outside air enters through eave vents near the attic floor, forcing existing hot moisture-laden air out through vents placed high on the roof or gable.

By ensuring proper insulation and ventilation, you will run less risk of the formation of ice dams and you will substantially reduce the likelihood of damaging your attic components.

To maintain the most efficient attic ventilation, make sure that vents from your bath, kitchen and laundry are not routed to the attic, but instead go directly to the outside.

Never block off your attic ventilation in winter, since moisture generated inside the house that rises to the attic can cause more problems in winter than in summer. With proper insulation between the attic floor and ceiling below, the ventilation will not lower the temperature in the house.