A Guide to Vents for Your Metal Roof
Metal roofs are quite popular among builders and homeowners because of their longer lifespan, energy efficiency, and durability. Metal roofing systems can last more than 50 years, making them an ideal choice compared to traditional shingle roofs that last for about 20 years. Metal roofs are generally more expensive up front when compared to asphalt shingles and other roofing materials. In the long term, the roof pays for itself through its low maintenance and longevity.
During the installation of metal roofs, one thing that is often overlooked is ventilation. Proper ventilation is important in designing and constructing any new roofing project. Ventilation contributes significantly to the performance of your metal roofing for overall effectiveness, energy use, and longevity.
How Does Ventilation Work?
When warm air is trapped in an open space of a building, it will rise to the highest point, usually the ridge. That is why vents are usually positioned close to the top of the roof to enable the warm air to escape. As the warm air exits the building through the vents on the roofing structure, cooler air is also drawn inside from the vents situated around the soffit or at the eave.
One major factor in a successful metal roof ventilation project is ensuring the same amount of airflow intake and airflow escape. To solve this, ventilation materials are quantified based on the net free ventilation area described as the total square inch area to make work easier for roofers.
What Happens if You Do Not Vent a Roof?
Lack of vents or poor ventilation of metal roofs means that the heat that builds up does not have an escape route. A buildup of heat can damage your metal roofing from the inside out. When your roof is evenly vented, it will allow the escape of hot air, keeping your roof and attic cooler.
Metal Roof Vent Types
Ridge Vents
Standard ridge vents are usually 10 feet long and are mainly used for architectural style metal roofs since they are designed to blend with the building’s shape, colour, and aesthetics perfectly. The venting materials are usually mounted on the metal roof panels and are covered using ridge cap flashing. Ridge vents are part of the building’s overall ventilation system.
Gable Vents
Gable vents are usually fixed at the peak of gables. Their work is to function as an exhaust or intake method based on the existing overall venting systems. Gable vents are mainly used for residential applications coupled with low-profile ridge vents.
Exhaust Vents
Like their name, exhaust vents allow exhaust to escape from the building. Ridge vents are the most common type of exhaust vents available. They are mainly made of high-impact molded copolymer. Exhaust vents may appear almost invisible, especially to untrained eyes.
Visible exhaust vents are mounted on the outer part of the metal roof. They include gable louvres, roof louvres, power attic ventilators, and wind turbines. Just like ridge vents, roof louvres and gable louvres work without electricity.
Wind turbines will also function without using a power source. However, they function optimally with a constant wind source and are less efficient than ridge vents. Power attic ventilators only operate on a power source. However, they are ideal for specific roof designs and can only be mounted in areas without excess wind.
Intake Vents
Intake vents are made from a copolymer material. They are usually located at the edge of the roof, at the eaves or under the soffit, under the panels at the roof edge, and on the drip edge. Intake vents work together with ridge vents to allow cool air to enter the attic space and force the exit of warm air through the ridge vents. Intake vents are usually more difficult to spot.
Benefits of Metal Roof Vents
Energy Efficiency Strategy
A metal roof may get relatively hot, and having a good ventilation system will help to eliminate heat from the attic. Ventilation is important because your attic will also be warmer when your roof becomes hot on a sunny day. And, as the attic heats up, your home or business will also become hotter. As a result, your air conditioner will have to work extra hard to eliminate this heat, increasing your energy use and costs. The best thing about metal roofs is that their reflectivity helps send away more of the sun’s rays compared to other roofing materials.
Condensation Issues
Activities carried out in homes can produce large amounts of moisture, for instance, doing laundry, bathing, cooking, and showering. Most of this moisture will migrate upwards towards your roof. When this moisture gets to the attic, it may condense on cooler surfaces resulting in mold and mildew that may affect the structural integrity of your home. A well-ventilated attic will ensure your insulation is always dry and more effective, eliminating condensation risks.
Avoiding Ice Dams in Winter
Ice dams are a major concern for areas that experience extreme winter weather. Ice dams occur when warm air from the house interior reaches the roof deck, causing the melting of the accumulated frozen precipitation. This liquid will run down your roof and refreeze on the roof overhangs, resulting in destructive and hazardous ice dams. The right roof ventilation will keep your attic temperatures more uniform, preventing the formation of ice dams.
Extends the Life of Your Roof
Your hot attic may heat up your roofing underlayment during the hot summer months, making it ineffective and brittle. Insufficient venting will result in a buildup of warm, moist air that can cause significant damage to your metal roof structure. As a result, having proper roof ventilation can help extend the life of your roofing system. In addition, it can protect your home’s structural integrity.
Reduces Indoor Temperature Extremes
Poorly ventilated metal roofs usually cause indoor temperature extremes. When your roofing systems are adequately vented to allow the escape of hot air and entry of cool air, the attic space and your home will be more comfortable to live in all year round. You will not experience warmer rooms on upper floors or your feet and hands feeling as cold as ice when the temperatures inside the house do not feel cool or cold.
How Many Roof Vents Do You Need?
The best way to determine the exact number of vents required for your specific metal roof is by asking your roofing contractor. Your roofing contractor will inform you of what works best for the metal roofing system being installed.
We Are Your Best Choice for Metal Roofing
If you are looking for a metal roofing system that lasts and suits your residential needs, Ironclad Roofing can help. We provide quality metal roofing products and unmatched customer service to residents of central and southern Ontario. With our experience, you can rest assured that we bring outstanding expertise to every roofing installation.
Originally published at https://www.ironcladroofs.com on May 22, 2022.
