A follow up to this question: Running Coax cable to the upper floor

If I cut a hole in the ceiling of my dining room and then another in the floor so I can run a conduit from the upstairs all the way to the basement, what should I use to secure the top and bottom of the conduit so it doesn't just fall through to the basement!

I need some kind of clamp (or maybe a bushing?) that will secure the conduit at the top (either on the ceiling of the dining room or the floor of the attic) and then again either at the floor of the dining room or the ceiling of the basement. I know I can clamp it to the wall (assuming I can find the stud), but it still seems like I should secure the top and bottom or else it could slide vertically out.

  • Securing it to the wall with a conduit clamp should do it. If it's not near a stud you attach a channel from stud to stud and secure the clamp to the channel. Perhaps you are looking for a less ugly solution?
    – Paul
    Aug 14, 2014 at 15:56
  • What type of conduit are you using?
    – Tester101
    Aug 14, 2014 at 15:56
  • @Tester101: I've not decided yet Aug 14, 2014 at 16:24
  • Reading your previous post, it looks like you'll be sheeting over the conduit eventually, but you mention stud-framed wall behind the conduit. why not run the wire/conduit inside the existing wall? Also, they make flexible conduit for data lines, sometimes called "smurf tube" because it is blue.
    – Paul
    Aug 14, 2014 at 16:29
  • @Paul: Because I figure it would be much easier to work outside the walls. Especially since it'll end up inside the wall eventually anyway. Aug 14, 2014 at 16:58

2 Answers 2


Depending on the type of conduit used, the codes for securing and supporting it are a bit different. In general, the conduit will have to be supported every 3-10 ft, depending on the type and size conduit used.

Fireblocking between floor may also be required.

International Residential Code 2012

Chapter 3 Building Planning

Section 302 Fire Resistant Construction

R302.11 Fireblocking. In combustible construction, fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier between stories, and between a top story and the roof space.

Fireblocking shall be provided in wood-frame construction in the following locations:

4. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion. The material filling this annular space shall not be required to meet the ASTM E 136 requirements

  • I've not seen any type of fireblocking done for any wiring/cable in houses I've owned/renovated and all passed inspections. Piping, ducts and vents I know need some type but wires/cables will depend on local code. Apr 20, 2017 at 17:28

If you use WireMold conduit (which isn't nearly as ugly as round conduit), you can screw the backing strip to drywall anchors, studs, whatever you have, then snap the conduit body on over the backing strip. That's about as anchored as it can get.

  • 1
    Surface raceways should not be confused with conduits -- you can't run the former in a concealed app! Apr 7, 2015 at 23:39
  • 1
    @ThreePhaseEel... I've only ever known WireMold as "conduit". True that it (or any other openable "wire contaier") should not be used in any fully concealed space. Fortunately, WireMold makes transitions ("connectors") for WireMold-to-conduit connections. Sep 5, 2015 at 22:50
  • Since the OP notes this is for coax cable, this comment is fully valid. I don't see any reason for anyone to have -1 it. Apr 20, 2017 at 17:21
  • @ClumsyHamster - ??? Apr 21, 2017 at 21:45

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