Roof ventilation is one of the most important elements of a roofing project. If your roof is not ventilated properly, it can lead to damages and repairs costing hundreds or even thousands of dollars. Surprisingly, this is a common problem for most homeowners. People often hire roofers who do not inform them or facilitate the understanding of a ventilation system for a roof. After reading this topic, you will learn everything you need about roofing ventilation.
What is roof ventilation? Why is it so important?
Ventilation is air cycling from outside into the attic and back out through the top of the roof. This allows for the attic to release moisture and heat. The attic allows air in through soffit vents at the eaves (or bottom front of the home) and expels the air from the top or ridge of the roof. This helps prevent mold, condensation, and other issues to occur on the roof. Condensation and heat can cause the roof deck (plywood under the shingles) to buckle or warp over time, and if not vented properly, can result in thousands of dollars in repairs and replacement (for both exterior and interior).
What are the different types of ventilation my roof can have?
There are many different venting systems. To keep things simple, we will cover 4 of the more common options used and their efficiency.
Although box vents are used to vent a roof, they aren’t the most efficient. Box vents create small areas in the attic that are not reached by the ventilation. Box vents can also be called “static vents.”
Turbines are also not as efficient in venting a roof. Not only is it very inefficient, but it also isn’t aesthetically appealing. Turbines are very large and will take a lot of space on the roof. It also doesn’t produce a continuous airflow through the attic.
Attic vents are not ideal for properly venting an attic. Not only is there a lot of wiring, but it also does not provide continuous airflow. Attic vents usually turn on when the air reaches a certain temperature.
Soffit and Ridge Vents
At the moment, the most efficient way to ventilate a roof/attic is by using soffit and ridge vents. These are holes or gaps in the soffits and ridge that allow continuous airflow in and out of the attic. This method allows for the air to vent continuously no matter the temperature. It helps the roof stay cooler in the summer and allows the entire roof to remain the same temperature in the winter (which helps with ice dams).
Common Mistakes Made When Ventilating A Roof
When installing any of these forms of ventilation, please make sure your roofer is certified by the manufacturer. Here are some potential problems if they are not knowledgeable.
- Covering the soffit vents in the attic with insulation. This makes the exhaust work harder to vent the intake of air. Make sure your roofer does not cover the soffit vents with insulation.
- Painting over soffit vents – A common mistake made by homeowners is painting over the soffit vents. This covers the intake and as mentioned before, it does not allow continuous airflow through the roof and attic.
- Not cutting a hole that fits the soffit vent properly. Some roofers install soffit vents without creating a proper opening for the air to enter the attic.
- Never install more than one exhaust system on a roof. When more than one exhaust system is installed, the stronger system begins to pull from the other one, then one exhaust becomes intake. It’s almost like drinking from a straw, when you have a hole in the straw, you end up sipping air rather than water. It is also not aesthetically appealing.