R905.1.2

Section 905.1.2 is titled 'Ice barriers' and covers requirements for roof coverings. The mandate for an ice barrier where required by another section of this code, for the ice barrier to be constructed of specific materials, and to extend a certain distance up the roof, dependent on the slope is established. The purpose of this section is to prevent water damage to the building. This section has an exception which exempts detached, unconditioned, accessory structures from ice barriers. The purpose for this exception is because unconditioned accessory structures are less likely to be damaged by back up of water from ice forming along the eaves.

The model shows a partial cutaway view of an asphalt shingle roof covering assembly which explodes and reassembles to show the installation order of components. The ice barrier is highlighted.