Article 330.12 prohibits MC cable when exposed to mechanical damage. 690.31(D) allows MC cable when intalled in an area that is not readily accessible. My client wants to install MC cable across the open roof of a building, arguing that access is restricted to qualified and trained personnel only so that qualifies as not readily accessible. the inspector feels that the open rooftop is readily accessible. This is a Target store in Southern California with an on-site maintenance team and the roof access under their control at all times. is MC cable ok?