MC cable

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joeyww12000

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Chatsworth GA
When running MC through metal studs on jobs Ive been on nothing has been done to protect the MC from punctures from screws. Today I noticed in some wood framing studs some MC had been ran through the studs and I wondered if there was a code for putting in nail plates for these situations. What would you do for metal framing? Is there a code at all for either situation?
 
When running MC through metal studs on jobs Ive been on nothing has been done to protect the MC from punctures from screws. Today I noticed in some wood framing studs some MC had been ran through the studs and I wondered if there was a code for putting in nail plates for these situations. What would you do for metal framing? Is there a code at all for either situation?

See 2008 NEC 330 Metal-Clad Cable: Type MC

See 2008 NEC 300.4 Protection Against Physical Damage

1 1/4" clearance from nearest edge

Do nothing for the metal framing. It has the proper clearance. Unless you might use a hole punch.
 
MC cable run horizontally through metal studs require no protection even if the size of the stud makes the cable closer than 1.25" from the face of the stud. When MC is installed through bored holes in wood studs the 1.25" requirement applies just like for NM cable.
 
MC cable run horizontally through metal studs require no protection even if the size of the stud makes the cable closer than 1.25" from the face of the stud. When MC is installed through bored holes in wood studs the 1.25" requirement applies just like for NM cable.

Rob,

I agree! I wonder what the intent here is? Wood vs. Metal studs. Heck I can take a 710 stud punch to a 1-5/8" stud and have a problem with possible penetrations.
 
Personally I don't see it as much of an issue. Since the punched hole in the stud is rather large the cable usually moves out of the way of the screw.
 
Thats interesting maybe the code panels thought that nails would be used in wood studs. Screws still can be as long as nails.:confused:
 
Thats interesting maybe the code panels thought that nails would be used in wood studs. Screws still can be as long as nails.:confused:

Or longer. Just because they don't have to use a 3" screw doesn't mean they won't.:smile: But that's not to say that Rob isn't right either.
 
It's my understanding that the prepunched holes are out of reach of screws. Metal studs are typ 3-5/8". I believe that 5/8" board is required. The usual screws are 1-5/8" leaving 2" of space in the center of the stud. There is an AHJ in a local jurisdiction that requires the use of a Caddy clip to hold the cable in the center of the stud. But like cowboyjwc wrote, the occasional 3" screw might find its way in.:mad:
 
The cable is not required to be held in the center of the hole in the stud. Metal studs come in all different sizes starting with 1 5/8". Even those will not require any additional protection to a horizontal cable running through the holes.
 
The cable is not required to be held in the center of the hole in the stud. Metal studs come in all different sizes starting with 1 5/8". Even those will not require any additional protection to a horizontal cable running through the holes.

I'm not disagreeing with you, I'm simply saying that it is still possible for a screw to hit it.
 
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