steel I beam as raceway?

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Old 01-27-09, 12:08 PM
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steel I beam as raceway?

I have two steel I beams in my basement supporting the joists. the carpenter just boxed them in for drywall guys. So now I have the two C shaped cavities per beam with vertical wood pieces every 24". can I lay wire in the beam since the wire is prevented from coming out by the wood? I can post pictures if anyone wants to see what I am talking about. If they are not bundled tightly, how many conductors without having to worry about derating? I guess it is like square shaped conduit but about 3" wide by 6" high with one side open, but with vertical blocks every 24" on that side.
 
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Old 01-27-09, 01:20 PM
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Pictures would help. The cable will still have to be supported somehow. Is the wood 2 X 4s?
 
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Old 01-27-09, 01:28 PM
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I'd suggest that you install some "stacker" cable clamps on the inside of the channel which each can hold 4 romex each. In the six inch space, I don't see why you couldn't do two runs of 4. Since you can't swing a hammer inside the channel to set the nail on the stacker clamp, you can use a C-clamp to push the nail into the vertical supports.
 
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Old 01-27-09, 02:36 PM
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that sounds like a good idea. I just used some of those elsewhere. Didn't particularly like the ones I used as they didn't really hold cable too tightly. It slides a lot in them. Is this the way that all of them are? I guess I can deal with that if needed. Here are some photos. the first shows the steel I beam in center with the HVAC duct on left and a 2x4 on the right. photo 2 shows a side view. You can see the aforementioned 2x4 at bottom and there are vertical short pieces of 2x4's 24" apart. I could drill the vertical pieces, but I think I would be limited in amount of cable that I could pull through the holes. The stackers would give me 8 wires on a side and I have 2 sides available (other two have HVAC)

<img src="http://i42.photobucket.com/albums/e311/hammerash/DSCN5372.jpg" width="640" height="480">
Click to see the original size.

<img src="http://i42.photobucket.com/albums/e311/hammerash/DSCN5374.jpg" width="640" height="480">
Click to see the original size.
 

Last edited by Rick Johnston; 01-27-09 at 04:18 PM. Reason: Reduce size of photos
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Old 01-27-09, 03:15 PM
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Am I the only one who can't see the pictures?

Had to check because I was a page off looking for intermatic spring operated timers in a different thread.
 
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Old 01-27-09, 05:13 PM
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looked a lot darker in the post than on my computer? Here are some more.
<img src="http://i42.photobucket.com/albums/e311/hammerash/DSCN5375.jpg" width="640" height="480">
Click to see the original size.

<img src="http://i42.photobucket.com/albums/e311/hammerash/DSCN5378.jpg" width="640" height="480">
Click to see the original size.
 

Last edited by Rick Johnston; 01-28-09 at 04:10 AM. Reason: Resize photos.
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Old 01-28-09, 06:28 AM
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Yes, you can use that soffit to run your cables. As pointed out you still have to support them. Also, it looks like the bottom boards are only 3/4". That is not the required 1 1/4" away from the face where they attach drywall so you may run your cable on them unless you use nail plates to protect the cables.
 
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Old 01-28-09, 06:35 AM
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sorry, I guess pictures aren't real clear. yes, you are right that the boards underneath are only 3/4". But the cable would be protected by the steel beam from underneath. so I wouldn't have to worry about protecting it. I wasn't sure whether I would have to support the cable in this space, but I see that I will.

thanks
 
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Old 01-28-09, 07:13 AM
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Pretty much the rule: If it is not fished, it needs to be supported per code.
 
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Old 01-28-09, 06:13 PM
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I would think that you could just lay the wires in there but I'm not for sure if it was my place I'd tape them or tie them together but im not an electrician
 
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Old 10-08-09, 11:36 AM
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been a while since original thread, but recently I was talking to an electrician acquaitance and he said that the cables could be placed in the steel I beam without being supported. Now he does do commercial and not much residential so I don't know if that matters. to refresh, I have steel I beams that have vertical pieces of wood boxing them in every 24". Everyone seemed to say that the cables would need to be supported so just wanted to clarify and see if maybe it is different in commercial wiring?
 
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Old 10-09-09, 01:09 PM
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Even in a commecial setting the cables would need to be secured at the proper intervals, unless fished.
 
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