You probably already know the basics of ventilation. Ventilation is the flow of air through a system of intake and exhaust. Ventilation is important because it extends the life of your roof, reduces energy costs, and reduces indoor temperature extremes. The need for roof ventilation wasn’t documented until the early- to the mid-20th century.
Now we’ll take a more in-depth look at how ventilation works for your home.
Proper ventilation in your attic helps address excess heat and moisture that can otherwise wreak havoc on your home. Heat and moisture buildup in an attic cause predictable but different problems in hot and cold climates; areas with hot summers and cold winters can suffer the effects of both.
1. Prevents Condensation, Mold, and Rot
One of the most important aspects of proper roof ventilation is to help prevent condensation, which ultimately leads to mould and rot. Your home produces a lot more moisture than you think. Laundry, showers and bathing, cooking and more all produce warm, damp air inside the living space of your home. This moisture gravitates upwards to your home’s ceilings, and if a vapour barrier is not in place, it eventually lands in the attic. If a cool surface, like the underside of your roof, is reached by the warm air, it will condense.
The condensation caused by this “trapping” of air can create an unhealthy environment prone to the biological growth of mould and mildew. Properly ventilating your roof and attic space keeps your insulation dry and prevents these condensation-caused damages.
2. Increases Energy Efficiency
Ensuring you have a proper attic and roof ventilation helps to reduce your home’s cooling costs by allowing heat to escape. As the temperatures outside begin to rise, the temperature inside your home does too. If you do not have proper ventilation, the heat will be trapped inside your home’s attic, causing your air conditioning to work harder. If proper ventilation is in place, it can lower both your home’s cooling and operating costs. Another way to increase your home’s energy efficiency is by installing a cool roof.
A cool roof system will create a higher solar reflectance and thermal emittance compared to other standard roofing materials. These metal roofing systems are designed to absorb less heat, therefore even further increasing your home’s energy efficiency.
3. Reduces Indoor Temperature Extremes
Have you ever walked upstairs and thought it was at least 10 degrees warmer than it was in your living room? Those who live in ranch-style homes may also notice that although the room doesn’t feel cool, your feet are as cold as ice. These indoor temperature extremes are often the result of poorly vented roofs. Once your roof is adequately vented to allow the hot air to escape and the cool air to enter the attic space, your home will be more comfortable year-round.
5. Increases Roof’s Lifespan
Not adequately ventilating your roof and attic can dramatically reduce the lifespan of your roof. As we mentioned, condensation, rot, and mould can be a result. A non-ventilated roof can also cause extremely hot attics, where the heat builds up and eventually causes damage to the wood framing, rafters, underlayment and more. Ensuring your roof is evenly and properly ventilated helps that air to escape and extends the lifetime of your roofing system.
6. Prevents Ice Damming
If you live in a climate where snow and ice occur, having proper attic ventilation minimizes your risk of experiencing damaging ice dams. Ice dams are typically caused by warm air reaching the roof deck, which then results in the snow on your roof melting. This melted snow can run down your roof and refreeze over the home’s overhangs, forming ice dams. Proper ventilation will do two things to help prevent these potentially harmful ice dams:
- Direct the warm air from your living space to the peak of your roof and then outdoors.
- Ideally, keep the attic close to the same temperature outside, therefore preventing melting snow.
If you identify or have concerns about any of the above warning signs, it’s wise to have your attic inspected by a certified roofing Melbourne contractor who can assess whether there’s enough ventilation.