Why Attic Ventilation Is Important
As a homeowner, it’s especially important that your attic is ventilated properly. A lack of ventilation can trap excess moisture in the attic and the structure of your home. When excess moisture is trapped, it can easily ruin your roof, your home’s structure, and even the health of those inside the home. In fact, it has been said that home’s with asphalt shingles may need the most ventilation in the attic. Most asphalt shingle manufacturers will include a warranty with your purchase due to the lack of knowledge on ventilation with certain materials. They may even give you a list of ventilation requirements with the product.
The Two Methods of Ventilation
Passive ventilation is the most common way to get airflow into your attic. This method of ventilation provides natural airflow based on the fact that hot air rises. Wind generated pressure may also be used in passive ventilation methods.
To assist an upward flow of air, natural convection is used. The air current is maintained through strategically placed vents in the attic. Some of these vents may even have wind-assisted exhausts which forces the air through more rapidly creating plenty of ventilation and airflow. Convection assisted ventilation is extremely effective when done properly. Placing vents near the soffits and at the very top of the attic on the ridge will give you the best results.
When you choose to go with a powered ventilation method you must make sure you have an adequate amount of intake air in the attic. You will need to offset the amount of air forced out of the attic by the forced ventilation system. With this method a mechanical vent is placed on the roof of your property which also links to the attic space. This vent displaces air at an amount of 1 cubic foot per minute while 50% of the ventilation is provided by vents under the eaves of your home. It’s important that the attic’s ventilation and airflow is properly balanced when using a powered ventilation method.
According to International Residential Code (IRC), your attic must meet the minimum requirements for ventilation openings. A 1/150 fraction of the space must be ventilated. Cross ventilation between flat floors is also a requirement of the code. The NRCA as well as the professionals you have hired will make sure that your attic’s ventilation is up to IRC standards.