What Are Roof Vents?
“Roof vent” is a common term often applied to everything from plumbing stacks, to even furnace vents and dryer exhausts. However, as we define roof vents we are specifically referring to the vents designed to remove hot stagnant summer air and moisture during winter months out of your attic. To see the different types of roof vents available, check out our blog post What Types & Styles of Roof Vents Are There?
How Important Are Roof Vents?
Roof vents are critical in determining the life expectancy of your roof, utility costs and preventing interior damage from condensation and moisture.
Can I Mix Ventilation Types?
This is a good question! All throughout the greater Atlanta area we see homes with mixed ventilation types. To find out more, read our article Can I Mix Different Roof Vent Types?
Roof Vents Keep Your Home Cool In The Summer
For most, summer signifies more time outside; ice cream, time with the kids, baseball, a return to the golf course and trips to the pool, but it also means the return of unrelenting heat. That’s why most homes are shielded by attic insulation, but if your attic isn’t vented then you are making your air conditioner and insulation work harder than necessary. After taking into account the sad fact that most Atlanta homes are under insulated, the strain hot temperatures place on AC units is severe.
Georgia summers, specifically the greater Atlanta area, can see asphalt shingles reach average temperatures of 125° F or more – some reports exceeding 150° F! This heat transfers from the shingles into your roof deck and lingers in the attic turning it into a veritable oven.
By installing a well-designed combination of soffit vents (intake) and roof vents (exhaust), fresh air can circulate through your attic and heated air can effectively escape. This will lower the burden on your air conditioner, insulation and your power bill.
Roof Vents Keep Your Home Dry In The Winter
So venting your attic in the summer makes sense, but how does opening it to cold air in the winter help?
In fact, the importance of cooling your attic in the winter has less to do with comfort or utilities, but everything to do with removing harmful moisture from your attic and preventing water damage to your home. The goal is to keep the air temperature below your roof deck, or inside your attic, as close as possible to the temperature above it, or outside of your home.
Moist air can enter your attic during the cold winter months in one of three ways:
- The most common and yet most overlooked way moisture enters homes in Atlanta is a result of heated living spaces. Heated air has a greater ability to hold moisture than cooler air. As the humid, hot air rises it finds its way into your attic, bringing water vapor along with it.
- The second potential source of moisture is snow and ice. While Atlanta doesn’t have the same severe snow and ice issues as other parts of the country, our winter weather is still harmful. As snow collects on your roof, the heat from an unvented attic causes the snow to melt. The melted snow runs down the roof slopes and freezes anew creating ice dams. As snow and ice continue to melt the water gets blocked by the ice dams and accumulates between the snow, ice and your shingles. The melted water and expanding ice then seeps under the shingles, penetrating the roof system. Now you have a wet roof deck highly susceptible to rot. Compounding matters, you also have moisture in your attic that spreads causing additional rotting, mold growth and other water damage. Proper ventilation prevents any rooftop snow from melting, avoids the formation of ice dams, and removes the risk of water damage to your roof.
- Like ice dams, yet more common for the Atlanta area is the build up of debris on roofs. Winter causes the trees the shed their leaves and create a damming effect. Water runs down the roof surface and encounters this debris. Having no place to go, water can back up the roof slope and under the shingles. From there moisture enters the home.
This article was originally published by Sparrow Exteriors, a home improvement contractor serving Greater Atlanta Georgia.