Myths about attic ventilation

Attic ventilation is a must for your house, but it will only be beneficial if you make sure your ventilation is optimally designed by avoiding a few common misconceptions.

  1. Only homes in warm climates need attic ventilation. Ventilation is important in all climates, but contrary to popular belief, it’s even more important in climates with frequent periods of cold weather. Cool, damp weather increases the risk of moisture buildup in your attic, which can lead to mold growth. Vents are often used in colder climates as a way to combat moisture retention. Ventilation removes this moisture, protecting your attic from damage. However, insulation is more responsible for heat retention than roof vents, and the sun can do more to warm up that space than a furnace.
  2. One or two attic vents are enough. Most attics are not built with enough ventilation. Passive ventilation systems, including gable vents, soffit vents and turbine vents don’t always provide sufficient air exchange. This is especially true if your roof cavity isn’t properly insulated. Passive attic vents are the vents installed in your attic during the construction to let moisture escape from an attic in the event moisture gets into the attic. Attic baffles don’t always help and are often unnecessary. An extension of the passive attic ventilation myth is that attic baffles are essential to maintain attic ventilation. They maintain an air space between the vent at the frieze block and the roof sheathing.
  3. Attics need as much airflow as possible. Many homeowners falsely assume that since their attics are extremely hot in the summer the best way to reduce their cooling load is to get the heat out of the attic. The problem is that most naturally ventilated attics don’t have enough air exchange to make a difference. In most attics, 1 sq. ft. of ventilation for every 300 sq. ft. of ceiling space is enough ventilation. Much more than this and you risk creating uncontrolled air leaks. The open spaces in your attic walls may also leave your roof vulnerable to wind damage.
  4. Powered fans are ideal for providing continuous airflow. Most consumers who have an electrician install a powered attic fan never consider the unintended consequences The ceiling between the house and attic are a significant source of air leakage. Once the attic fan turns on it will draw outside air through attic vents, but also cool conditioned air directly from the house through air leaks and recessed electrical lights. Powered fans are only beneficial when the temperature outside your home is cooler than inside your home.
  5. Attic vents make it harder to heat your home during the winter. Proper ventilation will allow for airflow, which can remove heat from the attic. But even good ventilation won’t be able to bring your attic heat level down to outdoor temperatures because the roof radiates heat into the attic. Air sealing and insulation can minimize the amount of heat that enters your rooms, so a cold attic won’t make your home cold.

If you have any questions about your attic vents, Yorkshire Roofing is always there to answer any questions you might have.

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