One aspect of metal roof installation that is commonly forgotten about is ventilation. Proper ventilation is essential in the design and construction of any new roofing project. Ventilation has a significant impact on the overall effectiveness, energy consumption, and longevity of your steel roofing.
How does ventilation work?
When warm air is trapped in a building’s open space, it rises to the highest point, which is usually the ridge. That is why vents are typically placed near the top of the roof to allow warm air to escape. Cooler air is drawn inside from vents located around the soffit or at the eave as warm air exits the building through the vents on the roofing structure.
Having the same amount of airflow intake and airflow escape is a key factor in a successful metal roof ventilation project. To address this, ventilation materials are quantified based on the net free ventilation area, which is defined as the total square inch area, to make roofers’ jobs easier.
Benefits of Steel Roofing Vents
- Energy Efficiency – Metal roofs get hot and proper ventilation helps to remove trapped heat.
- Preventing Ice Dams in the Winter – Steel roofing vents will help attic temperatures be more uniform, preventing the formation of ice dams.
- Condensation Issues – A well-ventilated attic will ensure your insulation is always dry.
- Extends the Life of Your Roof – Proper ventilation protects your roof’s underlayment.
- Reduces Indoor Temperature Extremes – Helps to keep the temperature in your home more uniform.
What happens if you don’t have a roof vent?
Without proper roof ventilation, you’re allowing your attic to remain at a high temperature. This can lead to unnecessary and premature damage to your roof. Roof vents improve air flow, which reduces moisture buildup in attics.
Types of Steel Roofing Vents
Standard ridge vents are typically 10 feet long and are primarily used on architectural style metal roofs because they are designed to perfectly blend with the shape, colour, and aesthetics of the building. These vents are usually mounted on metal roof panels and protected by ridge cap flashing.
Gable vents are typically installed at the peak of gables. Based on the existing overall venting systems, their job is to function as an exhaust or intake method. Gable vents are generally used in residential applications, in conjunction with low-profile ridge vents.
A copolymer material is used to make intake vents. 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 and ridge vents work together to allow cool air to enter the attic space while forcing warm air out through the ridge vents.
Exhaust vents, as the name implies, allow exhaust to exit the building. Ridge vents are the most commonly used type of exhaust vent. They are primarily constructed of high-impact molded copolymers. Exhaust vents may appear almost invisible, especially to untrained eyes.