How can I safely surface run two electrical Romex electrical cable from the attached garage panel through the second floor bedroom closet to the attic, while complying with North Carolina electrical codes and codes for passing wires through a firewall? The bedroom is located directly above the garage, which means there is likely a firewall between the two areas. I'd like to avoid passing new wires through the wall because the wall is spray foamed and is located above the electrical panel. I believe there are many existing wires in the wall that run to the HVAC attic air handler.

  • If access is possible, drill a hole through the top and bottom plates of the bedroom wall. Use pull sticks to pull the cables through the holes and seal with fireproof caulk. Don't know if the caulk is approved by NC code. Have to wait for the electric experts to chime in.
    – RMDman
    Apr 8, 2023 at 13:08
  • I'm planning to run wires on surface, I really don't want to pass wires through the wall because of the location. The wall is above the panel so the must be many existing wires in the wall already and the wall is spray foamed. Apr 8, 2023 at 13:12
  • 1
    That is good info to include in you question.
    – RMDman
    Apr 8, 2023 at 13:22
  • Sure, thank you. Apr 8, 2023 at 13:31
  • Whatcha wanna do with them in the attic?
    – Huesmann
    Apr 8, 2023 at 13:53

1 Answer 1


Surface running the wires means installing conduit and not using NM cable. You might want to install the conduit up the exterior wall from the garage to the attic. This is done frequently when replacing knob & tube wiring on different levels of a house. This avoids the firewall issue.

If you choose to do it your way, you'll need to get with your local building authority for acceptable fireproofing.

  • 2
    You can also use "wiremold" for a more finished look for surface mounting wire/cable, if desired.
    – FreeMan
    Apr 8, 2023 at 14:10
  • How can I do fireproofing when running inside house through firewall? Apr 8, 2023 at 14:17
  • Consider a new question specific to that question. In short, processes/products referred to as firestopping, and specifically for conduits and pipes, "firestop collars" - but also, as answered by JACK, see what your LAHJ requires/accepts bafore choosing something they may not accept. OP, also learn the difference between cables and wires, for clarity and correctness.
    – Ecnerwal
    Apr 8, 2023 at 15:27
  • JACK : It is permissible to use NM cable in conduit, you just have to upsize the conduit. In some situations, it can make the complete run without needing a permanantly accessible junction box and associated splices transitioning from THHN/THWN to NM. That or running conduit for the entire run, which in many cases is not practical. Apr 8, 2023 at 15:37
  • Should I use metal or pvc conduit? Apr 8, 2023 at 16:37

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