Taking down my ceiling to run some wire to new outlets. The outlets are going in an area with an unfinished ceiling, so I know the romex there will need to be ran through the joists when going perpendicular, to get to its destination.

On the way to the breaker box though, it's going through a finished ceiling. In that portion of finished ceiling, I noticed someone basically took nails, turned them sideways, and used that to secure the romex (home made staple).

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That got me thinking if I didn't have to bore through the joists in the finished area, and save me a ton of labor. I know the code is probably to prevent people from hanging stuff on the romex when it comes to unfinished ceilings, but still. I would use insulated staples instead of nails, but the concept is my question.

I also came across this on a separate site, but more confirmation doesn't hurt.


You can run cables across and under the joists. If you do though you must install them on running boards for protection. Typically it is just easier to drill.

National Electrical Code 2011

Chapter 3 Wiring Methods and Materials


II. Installation

334.15 Exposed Work.

(C) In Unfinished Basements and Crawl Spaces. Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two 6 AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards. Nonmetallic-sheathed cable installed on the wall of an unfinished basement shall be permitted to be installed in a listed conduit or tubing or shall be protected in accordance with 300.4. Conduit or tubing shall be provided with a suitable insulating bushing or adapter at the point the cable enters the raceway. The sheath of the nonmetallic-sheathed cable shall extend through the conduit or tubing and into the outlet or device box not less than 6 mm (¼ in.). The cable shall be secured within 300 mm (12 in.) of the point where the cable enters the conduit or tubing. Metal conduit, tubing, and metal outlet boxes shall be connected to an equipment grounding conductor complying with the provisions of 250.86 and 250.148.

  • If you are not putting the tiles back up you can simply staple the cables to the underside of those furring strips. – Speedy Petey Mar 8 '14 at 13:35
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    As for the bent over nails, surprisingly there is no requirement to use a listed securing device, so they would be technically legal. That said though it is NOT a good idea. Use proper cable staples. – Speedy Petey Mar 8 '14 at 13:37
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    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,... I wouldn't think bent over nails meet this requirement. – Tester101 Mar 10 '14 at 10:57

If I understand what you are asking, it is OK to staple romex along the side of a floor joist a safe distance from the edge to protect from screws or nails. It is not OK to "cross beam", meaning stringing the wire beam to beam under them. This is when you need to drill holes. As far as using bent nails as fasteners. That sounds like a bad idea since the bent nail could pinch or damage the cable and may not give you a secure support. I would suggest using a insulated romex staple and position your wire about mid way up on the beam.

  • I was going to do that (insulated staple), but this is referring to a finished ceiling in the basement. Do you have a code reference for this also? – MDMoore313 Mar 8 '14 at 12:49
  • I've updated my question with a picture for reference. – MDMoore313 Mar 8 '14 at 13:14
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    The pic shows a wire Cross beaming, which is not permitted in a finished or unfinished ceiling. I will defer to Tester for the NEC reference. I do not have the current text to quote from. – shirlock homes Mar 8 '14 at 13:32

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