So I have an old house (circa 1790) that I'm trying to install data cable into. It has 2 floors for living, and attic and a basement. The issue that I'm running into is that there are only a few places that reach from the basement (where the modem and switch are housed) to the attic and they all already have either plumbing or electrical wires running through them, and the walls are all plaster, which I don't want to mess with to make new routes. There's on spot in particular that would be ideal for getting a wire through (I managed to get fish tape from the attic to the basement with relative ease), but there is an electrical run already there. However, there is also a derelict coax cable already installed there as well, which was able to transmit HDTV with no problems when it was still in use. I'm wondering if that is a good enough sign that shielded Cat6 would perform ok there, or whether I should look into either fiber or finding another path down. The run would be about 70-80 ft total with 30 ft or so alongside the electrical. Thanks for your input!

Side note about the electric runs: the wires that are not in a conduit are only to connect the attic lights, which are seldom on, and then there is a shielded conduit which houses the power for the HVAC system up there.

  • 4
    You can cross off "sharing a pipe, conduit or hole with mains electrical cable", that is not allowed unless it is fiber and non-conductive. I have found plumbing routes to be most productive. Commented May 21, 2018 at 4:47
  • 1
    wifi was designed for these applications, and newer routers are actually faster than wired copper...
    – dandavis
    Commented May 21, 2018 at 19:46
  • We have a mesh system in place right now, but we're having issues getting decent bandwidth. Many of the interior walls are stone, which blocks the wifi radio for the most part.
    – Nate
    Commented May 22, 2018 at 13:51
  • Are you willing and able to put a conduit on the outside of the house? That might be the best way to do it while still meeting code.
    – mrog
    Commented May 22, 2018 at 21:25
  • @Harper -- while same conduit/raceway is indeed a no-no, same hole is fine (see Exception 1 to 800.133(A)(2)) Commented May 22, 2018 at 22:33

1 Answer 1


Unshielded twisted pair will perform fine along side 120V 60Hz wiring. Don't bother with shielded, it won't pull as easily and is more expensive and isn't needed for you. Twisted Pair will not have problems because of differential signaling. Plus you're only talking about 70-80 foot run, you could still run CAT 5e and get Gigabit. I'd be surprised if you see a single error on the interface. Modern Ethernet is amazingly resilient. This isn't like Thinnet, tokenring, or old coax days.

I'm not saying its to code, but you don't need to worry about EMI at least.

UTP Cabling and the Effects of EMI

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