How far must ice barriers extend from the lowest edges of all roof surfaces inside the exterior wall line of a building?

The correct answer indicates that ice barriers must extend 9 feet 2 inches from the lowest edges of all roof surfaces inside the exterior wall line of a building. This measurement is derived from building code requirements designed to prevent water infiltration due to ice damming, which can occur in colder climates. Ice barriers are critical in protecting the eaves and vulnerable areas of the roof by providing a secondary layer of protection under roofing materials.

The specific distance of 9 feet 2 inches is established to ensure that the barrier adequately covers the area most susceptible to ice accumulation and subsequent water leakage during warmer spells when the ice melts. By extending this barrier sufficiently, the risk of water entering the building and causing interior damage is significantly reduced.

In the context of building codes, the emphasis on exact measurements reflects the need for consistency and compliance across different structures, emphasizing the importance of thoroughness in preventive measures against weather-related damage to buildings.