The Building Subcode and the One- and Two-Family Dwelling Subcode contain requirements for roof coverings; in particular, the underlayment and flashing sections specifically require an “ice dam membrane” or “ice barrier” in Section 1507 and Section R905, respectively, in areas where the average daily temperature in January is 25°F or less. For the State of New Jersey, this area is Sussex County. Detached accessory structures that contain no conditioned floor area, regardless of location, are exempt from the ice dam membrane requirement. For specific roof covering installations, please refer to appropriate sections of the Building Subcode and the One- and Two-Family Dwelling Subcode, as applicable.