Proper Roof Ventilation: Why It's More Important Now Than Ever Before

With the continued push toward green building techniques and environmental sustainability, homes are being built to be increasingly energy-efficient. This is a good thing because not only does it lower our energy bills, but it also reduces the greenhouse gases we pump into the air through heating and cooling. But there's one element that often gets overlooked in making homes more energy-efficient, and that's making sure the roof and attic are properly ventilated. Roof ventilation has always been a good idea, but let's talk about why it's now more of a priority than ever.

Unintended Consequences for the Roof

The whole goal of energy-efficient windows/doors, insulated attic, walls, etc., is to prevent heat exchange with the outside. In other words, by keeping heat or air conditioning inside the home, the HVAC unit doesn't have to work as hard to maintain the inside temperature, saving energy in the process. But this can have unintended consequences for your roof because all that heat (and humidity) accumulates in the attic and rafters. This wasn't as much of an issue when homes were not so "airtight" and heat could escape from other places in the home. But now that those draft points are being sealed through insulation, double-paned windows, etc., hot air builds up in the attic with no place to escape. Without ventilation, this takes a toll on your roof and can severely shorten your roof life expectancy.

The Ways Improper Roof Ventilation Can Cause Damage

When your roof and attic are insufficiently ventilated, your roof ultimately pays the price. There are three main ways your roof can sustain damage through improper ventilation:

• Condensation, rot, and mold. Not only is heat building up in the attic--so is the humidity created by daily home life. The moisture from cooking, showers, and even breathing eventually makes its way to the roof. If the roof surface is cool outside, that moisture condenses onto the interior roof surface, which not only rots the materials and weakens the roof structure, but also can encourage the growth of harmful mold which deteriorates the roof and can even hurt the air quality inside the home.
• Excessive heat build-up. During the hot summer months, the air in the attic can become superheated from the sunlight beating on the roof. Without a method of heat exchange, this heat can begin to warp the roof substrate and weaken the integrity of the shingles. Ironically, this heat also counteracts the effects of your energy-efficient home by sending heat downward and making your A/C work harder.
• Ice damming. In climates where snow and ice are common (like here in New York), the heat build-up in the attic can cause damaging "ice dams" on the roof. As the hot air warms your roof, the snow layer against the roof begins to melt, then refreezes as it reaches the eaves. The resulting ice dams can create standing water as the snow melts, causing water to back up under the shingles and leak into the home, damaging your roof substrate and walls in the process.

How Roof Ventilation Solves These Problems

By installing a ventilation system in the roof, you can help to mitigate all of these risks. Proper roof ventilation relieves undue pressure on your roof caused by the accumulation of heat and humidity. It allows the hot air to escape in the summer, keeping your attic cooler. In winter, it creates a more balanced temperature between the roof and the home so ice dams don't form as easily. Most of all, it prevents moisture accumulation which can deteriorate the roof structure, allowing your roof to last longer before needing replacement.

What About Energy Efficiency?

Does having a ventilated roof make your home less energy efficient? Actually, in the long run, it improves energy efficiency. By allowing a healthy heat exchange through the roof, you're preventing the attic from becoming an oven and fighting against your air conditioner. The effects of heat loss in the winter months are minimal, and extending the life of your roof also helps protect the environment because you're consuming fewer building materials.

If you’re interested in protecting the roof life of your Long Island home, the experts at A1 Roofing can design and install a roof ventilation system perfect for your home’s needs. For more information, contact us today.