I need a 240v (intermittent load will be 14 A max) single phase outlet about 30 feet from my distribution panel in my finished basement. The distribution panel is outside on the first floor. I do not want to tear out the finished drywall and popcorn ceiling, and running wires inside the ceiling would be impossible without major damage.

Is a metal or plastic raceway required along the ceiling?

Can the outdoor rated 10/2 THNN wire be run along the ceiling with just hooks, where it is visible? The wire does not run along the wall.

What does the NEC require for finished basement wiring along the ceiling?

  • 2
    I'm a little confused on exactly what type of wire you're using -- usually THHN is individual wires rather than a cable that consists of several wires plus a common jacket, but you mention it's 10/2 which normally would specify a cable with 2 10-gauge wires (+ground). Which is it?
    – Nate S.
    Sep 27, 2019 at 18:27
  • There's no such thing as 10/2 THHN, and THHN is not rated for outdoor use. I think you need to review/clarify which wire or cable you are talking about specifically. Sep 28, 2019 at 0:50

3 Answers 3


You need a conduit. For that matter you would need a conduit if running them inside the ceiling space.

  • While dealing with the specifics of a different insulation type, this answer hits the various code sections for "individual wire use" and need for a conduit/raceway pretty well. diy.stackexchange.com/a/166439/18078
    – Ecnerwal
    Sep 27, 2019 at 18:29
  • Ecnerwal, thank you. I’ll check the link you provided. My previous searches only found unfinished basements and along walls. Where in the NEC does it specify conduit is required in a finished basement along the ceiling? I read it is required along walls for protection of the wires. Sep 27, 2019 at 19:43
  • 1
    An over-simplification: The NEC says wires and cables need to be protected. Wires are protected by conduit, regardless of location (in or on: walls, floor or ceiling). Cables are protected by being inaccessible, either by behind walls, or stapled in joist bays in unfinished spaces (attics, basement ceilings). Cables can also be run in conduit, but it's painful and usually not worth it. Cables and wires can be run in LISTED raceways.
    – longneck
    Sep 27, 2019 at 19:53

Individual wires of any kind require a conduit, raceway, gutter, etc. etc.

Regardless, however you plan to mount those wires (draped from hooks?) would also be illegal if you were using cable instead of wire. There is no way to do this in the way you imagine.

Homes need utility spaces. When people cashier those spaces to create additional finished/living space, this is the consequence. Finished square footage isn't free; hiring a "get anything through walls and ceilings" sort of electrician to do the job soup to nuts, is where you pay for that square footage.

If you prefer, you could have someone put a drop ceiling in there so you can pop off panels and get access.


How to run 10/2 THHN outdoor wire

  • THHN = Thermoplastic HighHeat Nylon coated
  • THWN = same but water resistant
  • XHHW = cross linked polyethylene (i.e. PEX) for insulation = tougher than nylon


You imply stranded wire by saying THHN which in layman's terms a single wire which per code (and common sense) must be run in some conduit or raceway meeting various requirements (for wire protection).

You say outdoor wire which would imply UF-B. Not unlike NM-B but UF-B is rated for outdoor exposure and burial in the ground, because it's insulation (unlike NM-B) can handle it. So a UF-B rated wire would be what u want it seems to not have to worry about fitting conduit.

note nonmetallic sheathed cable (NM-B or UF-B) per article 334 prohibits above suspended ceilings in commercial occupancies because contractors are animals with pliers and saws, also any multi-family dwelling exceeding 3 floors.

What does the NEC require for finished basement wiring along the ceiling?

the NEC is more of a guide and not a how you must do it. There's room for interpretation based on various sections. If a finished occupied living space with a 7' ceiling within arm's reach then NM-B (or UF-B) would reasonably be a no because of likelihood to be contacted. But a ceiling > 8' out of arm's reach with NM-B supported properly (even by hooks) in a non living space would not be a hard no. A finished ceiling doesn't necessarily = finished basement. 334.15(b) = wiring be protected from physical damage by approved means (conduit) where necessary.

  • also 334.15a = closely follow the surface. there is no rule outright prohibiting NonMetallic wire running on the outside of a finished wall or ceiling.
    – ron
    Sep 27, 2019 at 21:40

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