2603.4.1.3 Walk-in coolers.
BC § 2603.4.1.3
In nonsprinklered buildings, foam plastic having a thickness that does not exceed 4 inches (102 mm) and a maximum flame spread index of 75 is permitted without thermal barrier in walk-in coolers or freezer units where the aggregate floor area does not exceed 400 square feet (37 m 2 ) and the foam plastic is covered by a metal facing not less than 0.032-inch-thick (0.81 mm) aluminum or corrosion-resistant steel having a minimum base metal thickness of 0.016 inch (0.41 mm). A thickness of up to 10 inches (254 mm) is permitted where protected by a thermal barrier.













