NM Cable in Metal Studs
- Thread starter wboz
- Start date
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rcarroll
Senior Member
- Location
- Fort Collins, Colorado
Re: NM Cable in Metal Studs
As long as it's a type 3,4,or 5 building per 334.10 & protected per 300.4(B)(1) you will be ok to run romex.
As long as it's a type 3,4,or 5 building per 334.10 & protected per 300.4(B)(1) you will be ok to run romex.
southernboys
Senior Member
Re: NM Cable in Metal Studs
I thought there used to be a rule that you could not use nm in buildings over 3 storys? was there ever a rule about this or just a rumor?
I thought there used to be a rule that you could not use nm in buildings over 3 storys? was there ever a rule about this or just a rumor?
charlie
Senior Member
- Location
- Indianapolis
Re: NM Cable in Metal Studs
You are correct, the rule was there a couple of cycles ago but was changed.
You are correct, the rule was there a couple of cycles ago but was changed.
southernboys
Senior Member
Re: NM Cable in Metal Studs
apreciate it charlie I thought I was going crazy. hell im already there doing this for a living
apreciate it charlie I thought I was going crazy. hell im already there doing this for a living
allenwayne
Senior Member
Re: NM Cable in Metal Studs
I resemble that rematk
I resemble that rematk
Re: NM Cable in Metal Studs
You cannot use NM in a 4 story building unless the first floor is 100% parking. The exception for a first level that is 100% parking is really meant for places like Pittsburgh where the ground level changes 2 stories between the front and back of the building.
However, in the 1980s some states such as Massachusetts, Ohio, and Pennsylvania allowed 4 story and igher buildings to use type NM if the circuit was confined to a single floor. The idea was that the building will usually have a sprinkler system and by making branch circuits cheaper there would be more branch circuits leading to cooler branch circuits resulting in less net fire hazard. At the time there was even a plenum rated version of type NM. The idea fell by the wayside when somebody figured out a way to make type MC cable with aluminum armor which was a just as easy to install as type NM.
You cannot use NM in a 4 story building unless the first floor is 100% parking. The exception for a first level that is 100% parking is really meant for places like Pittsburgh where the ground level changes 2 stories between the front and back of the building.
However, in the 1980s some states such as Massachusetts, Ohio, and Pennsylvania allowed 4 story and igher buildings to use type NM if the circuit was confined to a single floor. The idea was that the building will usually have a sprinkler system and by making branch circuits cheaper there would be more branch circuits leading to cooler branch circuits resulting in less net fire hazard. At the time there was even a plenum rated version of type NM. The idea fell by the wayside when somebody figured out a way to make type MC cable with aluminum armor which was a just as easy to install as type NM.
- Location
- Massachusetts
Re: NM Cable in Metal Studs
MC5, the '3 story rule' has been removed from the NEC, you may use NM in a building with any number of stories.
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