Many homeowners underestimate how critical proper attic ventilation is for the health of their home.
An attic is more than a storage area. It is also a space to circulate the air within your home. An attic with inadequate ventilation can cause temperature and moisture problems, reducing the energy efficiency of a home. But having an attic that is over ventilated is not recommended either.
A well-ventilated attic also prevents ice dams from forming during the winter by keeping your roof colder, and can extend the life of your shingles by cooling your roof during the hot, summer weather.
Seek Professional Advice
Since each home requires different amounts of ventilation, it’s important to seek professional advice to analyze your home’s energy efficiency. The general rule is that every 300 square feet of ceiling space requires about one square foot of ventilated attic space. However, there are other factors that come into play, such as the true ventilation amount that is infiltrating the vent grates. The actual vent opening might not be considered true vent space.
There are signs you can look for to spot if your attic isn’t properly ventilated. If there is frost on the underside of your rafters, it can indicate that warm, moist air is trapped, causing condensation and then freezing on the wood. If your attic wood seems water-stained or is black, it can be a sign of mildew or rot. Other signs of condensation can be rusty nails in the wood and matted-down insulation.
While the right amount of attic ventilation can increase a home’s energy efficiency in hot weather, there are other ways to make your home more efficient. The color of your roof shingles, the amount of sun exposure and whether the attic is properly insulated can make a difference in maintaining energy efficiency.
Moisture Problems
Stopping moisture problems before they cause major damage is one of the greatest benefits of having a properly ventilated roof. Homeowners living in cooler climates receive the greatest benefits from a well-ventilated attic. Homeowners living in warmer climates don’t need to be as concerned about condensation as homeowners in colder climates do, since they don’t experience the extreme cold weather fluctuations.
Many people mistakenly believe that the reason attic ventilation is so important is because the rising heat becomes trapped in your attic. If this was happening, the problem would actually be caused by poor insulation, which would be warming your attic. If rising heat made its way into your attic, it would cause more condensation to form, leading to wood rot and to the deterioration of the insulation.
Measure Attic Temperature
Your attic temperature should be about the same as the outdoor air temperature. If you’re not sure what the temperature of your attic is, measure the temperature of your attic after sunset. Without the sun beating down on your roof, the temperature inside should match the temperature outdoors.
If you’re not sure how your roof vents work, or if they are even effective in ventilating your attic, talk to a roofer or roof inspector.
