Attic ventilation is an important part of proper sloped roof design, albeit one that’s often overlooked. In this blog, the residential and commercial roofing contractors at JTI Roofing explain how attic ventilation works and why it is important for sloped roofing systems.
How Attic Ventilation Works
Attic ventilation requires airflow to vent heat and moisture from the attic, and replace it with cool and fresh air. Airflow can be created in two ways:
Natural Ventilation — Natural or passive ventilation utilizes natural air movement to create continuous ventilation. Since hot and moist air tends to rise, it naturally collects at the roof peak, and is released through vents in the roof ridge. The resulting negative pressure pulls fresh air through intake vents at the roof soffits. A properly designed roof should have proportionally matched ridge and soffit vents.
Mechanical Ventilation — Mechanical or active ventilation can be used on large roofing systems as the sole attic ventilation system, or complementary to natural ventilation systems. Specially-designed exhaust fans are installed along parts of the roof where ventilation is needed the most, and can be installed on asphalt shingle and metal roofing systems. Typical exhaust fans are powered by electricity, but solar-powered options are also available.
The Benefits of Proper Attic Ventilation
A properly ventilated attic has the following benefits:
Prolonged Roofing Life Span — A cool attic helps prevent damage to the roofing structure caused by heat and moisture, which can result in warped decking and rotten wood components. Condensation may also damage the insulation. This helps prolong your roof’s service life and minimize the chances of unplanned repairs.
Improved Energy Efficiency — Trapped heat in the attic can increase your home’s indoor cooling requirements during the summer season, which can lead to higher utility bills. This is not a problem with properly-ventilated attics.
Improved Comfort — If you have converted your attic into a loft or spare room, a properly ventilated attic is much more comfortable to stay in. Items stored in the attic will also suffer little to no damage, thanks to cooler temperatures.