Proper sizing and placement of intake and exhaust vents are essential to maintain balanced attic ventilation, especially when installing a copper roof, which can last a lifetime but needs good airflow to prevent moisture buildup and temperature extremes. The general rule is to have equal amounts of intake and exhaust ventilation, usually measured in net free area (NFA). Intake vents, such as soffit vents, should allow fresh air to enter the attic, while exhaust vents at or near the roof ridge let hot air escape. For copper roofing, ventilation needs to be carefully sized to avoid trapping heat or moisture under the metal, which can cause premature aging of underlying materials. The amount of ventilation required depends on the attic size, but a common guideline is 1 square foot of NFA for every 150 square feet of attic floor area, split evenly between intake and exhaust. You can check existing vents by looking for unobstructed openings with mesh covers and estimating their NFA on product labels or manufacturer specs.
For a safe DIY check, inspect your soffits and ridge or gable vents to make sure they’re clear of debris, insulation, or paint that might block airflow. You can also look for signs like mildew or heat that might indicate poor ventilation inside the attic. However, because ventilation needs can be complex and tied to the specific copper system and roof shape, don’t hesitate to contact a professional roofer experienced with metal roofs. When you do, it’s helpful to ask how they calculate vent size based on your attic dimensions and copper roofing specifications, and how they ensure vents won’t compromise the copper’s longevity or your roof warranty. These questions will help you understand if they are considering airflow balance and material compatibility in their ventilation plan.