An estimated 90 percent of North American homes have improper attic ventilation. One reason for this is that most homeowners are unaware of its importance. During the summertime, improper ventilation causes temperatures in the attic to build up beyond 160 degrees F. This very hot air eventually passes through the home’s insulation into the living area beneath it. While the homeowner may recognize that the attic is hot, they may not know just how hot it can become.

Excess heat can damage a home in a variety of ways, including damage to both exterior and interior paint. Other items that can be affected are wallpaper and exterior siding. Wood framing may warp, crack or break down. This can also result in what have been dubbed fried shingles, or the premature aging of a home’s roofing system.

When properly ventilated, there is continual airflow from the outside through the attic. The air intake is balanced between the soffits, or eaves, and the air exhaust, which is found at or near the roof’s ridge. This protects the insulation’s efficiency and helps to lower the living space temperature in the area below.

An attic with proper ventilation helps to reduce energy costs by lowering the load on a home’s air conditioning unit. The vents move the air out of the attic before it builds up, causing damage.

During winter months, moisture can increase in attics without proper ventilation. This is often caused by vapors from appliances, as well as by showering and bathing. When condensation accumulates, it can fall on attic insulation and soak the material, making it less efficient. Excess moisture accumulating in an attic can cause shingles to buckle and mildew to grow.

The Federal Housing Administration (FHA) recommends using a minimum of one square foot of ventilation in the attic for every 300 square feet, dividing the vent area evenly between the intake and exhaust. A roofing contractor can assist the homeowner in calculating the proper ratio, if necessary.

There are a variety of products available to ensure proper ventilation of the home’s attic. Exhaust items include rigid vents with snow guards, turbines, fans and roof louvers. There are solar-powered models, electric one and even some using dual power sources. Similar vent items are available as intake products for attics and other home areas, such as foundation vents, fans for the whole house and gable louvers. For those seeking ventilation and protection from snow for their chimneys as well, reliable roofers can help steer them in the right direction with roof caps, safety caps and other accessories.