Walls exposed to combustible buildings. Protection

The wall on the exposed side of a storage building within 50 feet of a combustible building, forest, piles of combustible material and similar exposure hazards shall be of fire resistive or noncombustible construction. In lieu of the fire-resistive or noncombustible wall, other better means of exposure protection such as outside automatic sprinklers or free standing walls may be used. The roof coverings shall be Class C or better, as defined in Roof Coverings, NFPA No. 203.