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I'm in the process of finishing my basement and, aside from a ground wire that was run under the floor joists, I have a fairly clear path for drywalling the ceiling along the floor joists. I have contacted the builder and they are refusing to address the issue. I've done some research on the subject and I've found other answers on this site pertaining to NEC codes for hanging wire to floor joists, but I believe the code doesn't specifically address my situation because the ground wire is a single 2 AWG conductor, while the NEC code (from the sections I've read) specifically call out two 6 AWG and three 8 AWG conductors. I've tried to find any additional information on this subject, which might be directly relevant to my case, but I haven't been able to locate anything. Is there a specific section of the NEC that addresses this case? Is a single conductor 2 AWG run under the floor joists up to code? If this is to code, how would you recommend I hang the drywall?

As a side note, I am not a contractor and I'm essentially trying to learn framing and drywalling by watching YouTube videos, so it's not that I'm trying to be a pain, but having the cable run through the joists (rather than under) would make my life significantly easier.

National Electrical Code 2011

Chapter 3 Wiring Methods and Materials

Article 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS

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.

Edit: Added image

Joists with ground wire

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  • 3
    So what is your question? How to enclose your space with the ground there?
    – Ed Beal
    Feb 3, 2021 at 16:49
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    As in what is required? The larger wire is ok to be run without a backer board. Smaller than 6awg require protection 250.64 would be the most direct code section (grounding electrode conductor instillation.
    – Ed Beal
    Feb 3, 2021 at 17:03
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    The photo shows the issue I am bringing up, OP would be attaching drywall with the ground wire between the drywall sheet and the bottom edges of the floor joint. "how would you recommend I hang the drywall?" - I would recommend notching and covering with nail plates or rerouting through holes like at the beginning of the run.
    – Programmer66
    Feb 3, 2021 at 21:15
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    @Programmer66 When I squint at the picture I see I-joists. Notching any joist is not recommended, but it is particularly hazardous to notch the flange in an I-joist.
    – HABO
    Feb 3, 2021 at 21:30
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    Drilling those I joists is ok. You would not notch them. If you want to hang the Sheetrock directly to the joists you need to move the ground over to the duct work or drill and re-route ground wire itself. If you decide to reroute turn the power off prior to disconnecting. I am not sure why they ran through some then under? Maybe to save some wire? If you want to use furring strips so you don’t have to mess with the plumbing or the ground that would be another possibility the wire needs to run 1-1/4” away from the furring strip see 300.4.D exhibit 300.2. Easy to remember same as depth 1-1/4”
    – Ed Beal
    Feb 3, 2021 at 23:42

1 Answer 1

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Your #2 wire is large enough to be run without protection or a backer if running perpendicular to the joists in the basement ceiling. 250.64.B.3 requires wires smaller than #6 to be protected. The basement ceiling is considered a safe location and the specific height is not given. 334.15 provides the examples of attachment as you have mentioned. I would caution that some older code answers are not current code as code has had significant changes in the last few cycles. (Each cycle is normally 3 years).

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  • Thank you very much for the answer. I don't think this changes anything, but the floor joists are ~8 feet off the basement slab, so that should be more than adequate to pass code.
    – senfo
    Feb 3, 2021 at 17:29
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    As I understand it, @senfo, the height off the floor is for required protection (either conduit or a chase). Ed's talking about whether or not the wire is allowed to be self-supported when spanning the space between joists.
    – FreeMan
    Feb 3, 2021 at 17:47
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    @ freeman see the code reference the same code is used for crawl spaces and basements it doesn't specify the height. Most inspectors use 8’ as that is the minimum height for protection of live circuits. But the examples are unprotected cables.
    – Ed Beal
    Feb 3, 2021 at 18:10

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