What is the required ice dam protection distance horizontally from inside the exterior wall for a roof with less than 4:12 slope?

For roofs with a slope of less than 4:12, the building code mandates specific ice dam protection to prevent water from pooling and leaking into the structure. The requirement states that ice dam protection must extend horizontally from the interior wall a distance of 36 inches. This distance is essential to ensure that the vulnerable areas of the roof, where ice dams are likely to form, are adequately protected from potential water damage during freezing and thawing cycles.

This regulation addresses the particular challenges presented by low-slope roofing, where the runoff of melted snow and ice may not drain effectively, thus increasing the risk of water infiltrating the building’s envelope. The 36-inch requirement ensures a buffer zone that can accommodate potential ice buildup, thereby enhancing the longevity and safety of the roofing system.

Other distances mentioned, such as 24 inches, 30 inches, and 12 inches, do not fulfill the protective measures necessary for low-slope roofs, making them insufficient to adequately prevent water intrusion due to ice dams.