Why is Proper Attic Ventilation so Important?



Key reasons to vent your attic:

  • Removes the moisture that passes through your ceiling of your living space.
    The average family of four can produce 2-4 gallons of moisture vapor a day by cooking, doing laundry, taking showers, and  just breathing. The moisture rises through the ceiling and into your attic. In the winter, moisture will condense as frost and water droplets that can drip onto the insulation. This can contribute to mold, mildew, & wood rot. 
  •  Prevents excess heat buildup in the summer.  On a 90 degree day, a closed attic can reach 130 degrees or more. Proper ventilation will reduce the attic temperature up to 40 degrees. With the reduction of radiant heat passing through your ceiling from your attic, your cooling bills will be lower and your air conditioner will last longer. 
  •  Increases the life of your shingles. Too much heat in the attic, increases the rate of embrittlement of your shingles by reducing the rate of oxidation and volatilization of the asphalt shingle hydrocarbons.  In fact, most warranties can be voided by the manufacturer if there is inadequate attic ventilation. 
  •  Reduces the chance of ice dams.  Heat from your home will melt the snow on your roof. The melted snow refreezes when it reaches the eave of your home causing ice dams. Proper ventilation will remove the heat before it melts the snow.


Conclusion: Proper ventilation starts with intake at the lowest part of your attic (the soffit) and exhaust at the peak (the ridge). You can reduce the moisture in your attic to avoid water damage, lower your electric bills in the summer, extend the life of the shingle, conform to the shingle manufacturer's warranty, and reduce ice dams.