A18.   Where a cold room has a floor area exceeding 20 m², a separate outer layer of noncombustible construction, including the door, having minimum 1-hour fire resistance rating (with sprinkler), shall be provided to compartmentalize the cold room enclosure from other areas. Provision of the fire resisting outer layer enclosure, including the fire door to the cold room would not be required if the cold room has a floor area not exceeding 20 m² and is sprinkler protected. The storage materials shall not include highly flammable chemicals. Cold room lesser than 20 m² provided with at least one hour fire rating compartment, need not be provided with sprinklers provided that the storage shall not include flammable materials.