Running NM cable in furred out residential walls


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Old 03-05-19, 01:29 PM
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Running NM cable in furred out residential walls

I am remodeling my home in Pennsylvania. It is a rowhome, with concrete block party walls. The walls are all open at this point. I will be leaving the original furring strips in place and installing new drywall once the project is complete.

My question is about running NM cable down from the upper floors to the service panel in the basement. I have secured the NM cable to the concrete block every 4 feet vertically. Is this OK? Does the cable have to be metallic, or in a conduit of some sort? It will not be penetrating the block at any point, just straight vertical homeruns.

Thanks in advance.
 
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Old 03-06-19, 06:33 AM
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How deep are the furing strips off the block?
 
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Old 03-06-19, 06:59 AM
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1 by, so 3/4". With 1/2" drywall to hopefully give me the 1-1/4" clearance from nails and whatnot.
 
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Old 03-06-19, 07:25 AM
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How were the electric boxes done before? You really need more than that for most electric boxes. I'd go with 2x2s (actual 1x1). (Guessing a bit. What is so 3/4"?)
 
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Old 03-06-19, 09:31 AM
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The boxes were originally placed in cutouts, where the block was chipped away. I'm not sure how many cubic inches they are, but they're not shallow by any means.
 
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Old 03-06-19, 03:50 PM
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Run the cables at least 1 1/4" off to the side of furring strips.
 
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Old 03-06-19, 04:29 PM
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Add to the furring strips. 3/4" is not enough room for your device boxes. Even handy boxes will be too small.
 
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Old 03-07-19, 06:31 AM
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Hi, are the outlet fed now, how was that done?
Geo
 
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Old 03-07-19, 07:08 AM
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The outlets were fed by older NM cable, kind of a silver braided cover. Those old, probably original from the 70s cables, didn't even looked to be secured vertically in the walls. My only concern is if code allows me to secure the NM cable directly to the block, as opposed to needed to go armored or conduit. It won't be exposed anywhere, except possibly at the termination point where they enter the breaker box in the basement.
 
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Old 03-07-19, 08:30 AM
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no problem securing to block. The 3/4" gap however is a problem. When going through a stud you require 1-1/4" gap to prevent damage. I'm not sure how that applies to drywall gap between studs.
 
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Old 03-07-19, 02:03 PM
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Here are some graphics to help from Mike Holt's site.

https://www.google.com/search?q=mike...C3B1W4RO6YRTM:
 
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Old 03-07-19, 02:52 PM
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When going through a stud you require 1-1/4" gap to prevent damage.
Sounds like he won't be running wires through the furring strips.

just straight vertical homeruns
 
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Old 03-07-19, 03:38 PM
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Sounds like he won't be running wires through the furring strips.
I realize that, but is the 3/4 gap behind the drywall OK. If the cables were being fished I think it might be OK but the drywall is not up yet so the cables need fastening every 4 feet.
 
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Old 03-07-19, 05:05 PM
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The fact that such small furring strips were used doesn't mean it was the best choice. The wall is open why not do it better.
 
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Old 03-11-19, 01:53 PM
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I realize that, but is the 3/4 gap behind the drywall OK. If the cables were being fished I think it might be OK but the drywall is not up yet so the cables need fastening every 4 feet.
I misinterpreted your post. My apologies.
 
 

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