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Clearance between roof decking and electrical conduit

Clearance between roof decking and electrical conduit

Clearance between roof decking and electrical conduit

Does the NEC specify a clearance between the bottom of roof decking and electrical conduit?  We are replacing part of the plant roof and some of the 277 lighting conduit runs along the bottom of the roof decking.  I am worried about a roofer running a screw into the conduit as they secure the insulation.  Any suggestions, Thanks.

RE: Clearance between roof decking and electrical conduit

Sounds like you are only replacing the roof membrane and not the roof deck.  The conduit should have been attached to strucutural members that support the roof deck and not the roof deck itself.  If it is not a major effort, I would recommend re-routing the conduit by attaching it to structural steel other than roof deck.

Ram K. Kondapi

RE: Clearance between roof decking and electrical conduit

if you look in the NEC - Article 300.4 - sub-section D -
Cables and raceways parallel to framing members., it says that you must maintain a 1 1/4" clearance form the nearest edge of the framing member ( or deck ) in your instance.
   if you are less thaan that a 1/16" steel plate may be installed to prevent puncture if not in conduit.

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