What Are the Rules for Roof Ventilation? A Code-Based Guide (and How Venting Supports the 5 Functional Requirements of a Roof)
Most homes follow International Residential Code R806 style rules for attic ventilation to the outdoors, size vents using the 1/150 rule (or 1/300 when conditions allow), keep intake and exhaust balanced, and protect openings with screens and weather protection. I work on Minnesota roofs, and our cold winters make moisture control and ice dam prevention…
