Attic ventilation is very important to ensure the longevity and effectiveness of a roofing system. Vapors and condensation that cannot escape a home can cripple R-values and result in the hidden decay of a building’s structure. Millard Roofing’s expert personnel will create a ventilation system that performs in every way—even the ways that you can’t always see.
It has been estimated that 9 out of 10 homes in North America suffer from improper attic ventilation. How does this happen? Often, people are unaware of the impact that attic ventilation has on increasing the longevity of an entire building.
For example, a home that is improperly ventilated can cause heat to build up to 160 degrees Fahrenheit during the summer months. This hot air will eventually penetrate through the ceiling insulation and into the living areas below.
Damage can occur due to poor attic ventilation:
- Shortened lifespan of your roof system (“fried” shingles)
- Warping, cracking, and creak down of a home’s wood decking
- Siding damage, exterior or interior paint damage, and wallpaper damage
- Increased energy costs
An attic that is properly ventilated will help to reduce the work that has to be done by your air conditioner. The ventilation will move the hot air out of your attic before it causes the kind of damage listed above. Also, household appliances such as bathtubs, showers, and cooking appliances can create an abundance of moisture in homes during the winter months. Poor attic ventilation will cause this moisture to collect and cling to the underside of the roof, as it cannot be released into the outdoors. As the moisture builds up, it will condense and fall. This moisture will soak the insulation on the attic floor and reduce its ability to insulate your home.
Additional structure damages may include the following:
- Warping and rotting of the wood framing of the home’s roof deck
- Growth of mold and mildew
- Buckling of roof felting and roof shingles
Finally, attics need to have proper ventilation to prevent the formation of ice dams in cold northern climates. In winter, ice and snow on a roof will eventually melt and run down the roof to the cooler eaves. Once the run-off reaches these cooler areas, it can freeze once again. This will form an ice dam that will trap water on the roof. The trapped water can eventually back up so that it seeps under the roof’s shingles and into the home. Once this happens, the water can cause hundreds or thousands of dollars in damaged ceilings and walls. However, an adequately ventilated attic will reduce the initial melting on your roof. This will reduce the chance that an ice dam will occur.
Proper Attic Ventilation
When an attic ventilation system works properly, it allows air to flow continuously into the attic from outside. This process protects the efficiency of a home’s insulation and also helps to lower the temperature in the living space below the attic.
Attic ventilation works to balance a home’s air intake (at the roof eaves of soffits) and air exhaust (at or around the roof’s ridge).
The Federal Housing Administration recommends that at least one square foot of attic ventilation should be installed (for both intake and exhaust) for every 300 square feet of attic space. This means that if your attic is 900 square feet, you need to have at least 3 square feet of ventilation. This amount is typically divided equally: half for intake and half for exhaust. Therefore your attic would have 1½ feet for intake and 1½ feet for exhaust. This system will ensure that air flows properly through your attic.