Proper Attic Ventilation
Proper attic ventilation systems allow a continual flow of outside air through the attic, protecting the efficiency of the insulation and helping to lower temperatures in the living space.
It consists of a balance between air intake (at your eaves or soffits) and air exhaust (at or near your roof ridge).
The U.S. FHA (Federal Housing Administration) recommends aminimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space. For example, if your attic is 900 square feet, you need a total of 3 square feet of ventilation. This amount should be divided equally between intake and exhaust ventilation.
Many homes in North America do not have proper attic ventilation. Why? Because most people are unaware that attic ventilation can impact the longevity of their entire home! In the summer, improper ventilation can cause attic heat to build in excess of 160°F. This super-heated air eventually penetrates the ceiling insulation into the living area below.
A properly ventilated attic can help reduce the load on your air conditioner by moving the super-heated air out of your attic before it builds up and causes damage. In the winter, various household appliances, bathtubs, showers, and cooking vapors can contribute to excess moisture build-up. Improperly ventilated attics will allow this moisture to collect and cling to the underside of the roof. The moisture will condense and fall, soaking the attic insulation and reducing its efficiency.
Finally, attics should be properly ventilated to help prevent ice dams in cold northern climates. During the winter, ice and snow on a roof will melt and run down the deck to the cooler eaves. This run-off can re-freeze, creating an ice dam that may force water back up under the shingles and leak into your home — causing hundreds or thousands of dollars of damage to your ceilings and walls. Adequate attic ventilation reduces the amount of initial melting that occurs on your roof, thereby reducing the chance that ice dams will form.
In the summer, good attic ventilation reduces heat buildup. That cuts cooling costs and prolongs shingle life. In the winter, warm, moist air seeps into the attic from the living space below. Good ventilation allows the heat and moisture to escape. That keeps your attic dry and reduces ice dams. Here are four signs of an unventilated or under ventilated attic:
During the winter Ice Dams can be a big problem. We are experts at removing snow and ice from your roof and can suggest cost-effective solutions such as electric roof deicing cables (heat coils or heat tape), ice panels, or gutter covers to help to prevent ice build up in critical areas.
An ice dam is a wall of ice that forms at the edge of the roof, usually at the gutters or soffit. When it forms the water then backs up behind the ice dam and creates a pool of water. This pool of water can leak into your home and cause damage to walls, ceilings, insulation, and other areas.
Ice dams are usually caused by heavy snowfall and improper ventilation in the attic. This causes warmer areas in your attic then the snow begins to melt, even when the outside temperature is well below freezing. When the accumulated snow on your roof starts melting it runs down your roof underneath the snow until it reaches a “colder” section like the soffit’s, valleys or in gutters then it begins to freeze again, this process of thawing and refreezing is what causes an ice dam. Cleaning the gutters on your home can help prevent ice dams from occurring as quickly but they can still occur if the conditions are right. The gutters will be just as cold as it is outside and in some cases, full of frozen debris. So even if you don’t have a soffit for the water to refreeze in, the melted water will most likely refreeze when flowing into the gutters.
WARNING! Performing ice dam removal is risking severe personal injury and damage to the roof if not done properly. Never walk on a snow covered roof and make sure if your using a ladder you follow the proper safety procedures. We highly recommend contacting professionals (like us) with the proper equipment and roofing experience to carry out this job.