I use NM staples to secure NM cable to wood studs but I am unfamiliar with the options to secure NM cable directly to metal studs despite trying a number of different search terms. Would it be okay to substitute metal screws in place of the nails using plastic NM staples which come with nails or would that void the UL listing of the staples? Or, is there another recommended method? I know for horizontal runs I can go through the center of the stud (also, I believe that counts as supporting, but not securing as per NEC:2011 section 334.30). Also, for this case I need to secure and support a vertical run down from the ceiling to an electrical box.
The Preferred Solution will:
secure the wire to the edge of the metal stud. The back edge of the stud faces the cinderblock foundation of my house and there is an air gap between the stud and the foundation wall.
not involve wood or other organic materials since the wall is in a basement and I am trying to avoid materials that could potentially breed mold (moisture is currently well under control, but you never know what the future holds). E.g. Attach wood to the stud and then use NM staples to secure to the wood.
334.30 Securing and Supporting.
Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (41⁄2 ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge. Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.