Protection Against Physical Damage

The protection against physical damage requirements for conductors, raceways and cables are outlined in Sec. 300.4 of the 2011 NEC.

June 19, 2014

When installed under metal-corrugated sheet roof decking, cables, raceways, and enclosures are permitted in concealed locations of metal-corrugated sheet decking type roofing if they are at least 2 in. away from a structural support member.

a) True
b) False

See answer and applicable Code reference

The correct answer is: b) False

The protection against physical damage requirements for conductors, raceways and cables are outlined in Sec. 300.4 of the 2011 NEC. As per 300.4(E), "A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 1 1/2 in. measured from the lowest surface of the roof decking to the top of the cable, raceway, or box. A cable , raceway or box shall not be installed in concealed locations in metal-corrugated, sheet decking-type roof."