Maintaining the integrity of your asphalt shingle roof often depends on having proper ventilation and air flowing through your attic. If air is not circulating properly throughout the attic, moisture can accrue from the stagnant air, eventually turning into condensation which can damage the interior of your home and the roof deck. For this reason, having a proper environment in your attic is essential for protecting the longevity of your home and roof.
The Essentials of Proper Attic Ventilation
There are three essential components to properly constructing an attic and ensuring that it has a healthy ventilation system. Good roof vents are very important for promoting continuous airflow throughout the attic. In addition, soffit vents and adequate insulation are also key components of a well-functioning attic ventilation system.
To have a properly functioning ventilation system, air must flow into the attic through the soffits, which are normally located under the eaves of the roof. The air then circulates throughout the attic and flows up and out through the roof vents in the upper portion of the roof.
Having adequate insulation in the interior walls of the home is important because it prevent heated or cooled air inside the home from escaping through the attic. You also need to ensure that you have properly sealed attic floor penetrations around the hatchways and the exhaust fans in the home.
Damage From Stagnate Air and Trapped Moisture
When air is flowing properly through the soffits and out through the roof vents, moisture will not get trapped in the attic and form condensation. However, when these safeguards are not in place and air is allowed to become stagnate, condensation will form in the attic, causing mildew and wood rot to develop in your roof deck. This condensation can even get into the insulation and leak through the ceilings of your home. In the winter months, it can cause snow on the roof to melt and form streams of water under the ice that flows back up through the roof shingles and leaks into your home.
Having Low Profile Roof Vents
Normal low profile roof vents have approximately 50 square inches of vent area that is net free and can be placed in equal spaces along the upper part of the slanted roof in the back of your home. These vents are specially designed to keep out water that may run down the roof during rainy weather and are fully enclosed with louvers to keep out birds and other animals. A roofing contractor can calculate the square footage of your attic space to determine the best number of roof vents that you should install.
According to the U.S. Federal Housing Administration, it is recommended that at least a square foot of attic ventilation is placed for every 300 feet of space in your attic. So, if your attic is 900 square feet, you need at least 3 square feet of ventilation for adequate coverage. This amount should be equally divided between the intake and exhaust ventilation to ensure proper air flow throughout the attic.
Low profile roof vents are considered to be a passive form of roof ventilation since they are not powered to pull air out of the attic, but only to allow air to escape on its own. Instead, the wind and natural breezes pull the air out of the attic. If in doubt you should have a Vancouver roofing company come in and inspect the roof. At the vert least you’ll know what kind of shape your roof is in and whether or not it needs any work done.