# Running MC ceiling



## Southeast Power (Jan 18, 2009)

Arikculwell said:


> So in a 16 unit dwelling single story what is the proper way to run mc cable? Like its not a droped ceiling, do i need to drill holes through joists? Run against walk boards, runwild or keeps squared up?


My first thought was, screw that and just use EMT then I thought, why MC? Why not just use Romex?
Answer is, you have to install it just the way you install Romex.


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## Arikculwell (Feb 16, 2016)

Well its connected to a commercial kirchen and offices so chief inspector said the units must be in mc aswell. But thanks.


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## macmikeman (Jan 23, 2007)

Arikculwell said:


> Well its connected to a commercial kirchen and offices so chief inspector said the units must be in mc aswell. But thanks.


Regardless of what the chief inspector says, what does your code book say about which methods are allowed to be used for this type of structure?
I look there first before I go asking ''how do I do this''.


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## sbrn33 (Mar 15, 2007)

16 unit single story? Don't see that everyday. If I was an inspector I would also classify this as commercial or I would make you have firewalls in between the commercial side and the resi. Mac, in the Midwest a lot of places require commercial to be conduit or MC.


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## macmikeman (Jan 23, 2007)

sbrn33 said:


> 16 unit single story? Don't see that everyday. If I was an inspector I would also classify this as commercial or I would make you have firewalls in between the commercial side and the resi. Mac, in the Midwest a lot of places require commercial to be conduit or MC.


I don't blame them due to seeing what rodents can do to romex. However, having said that, written amendments to code are required , not just some ''chief inspector'' and the old '' this is how I like it'' . People love spending other peoples money for them altruistically. Chief inspectors included. 

Number of floors is not the consideration any longer, the type of building construction is. See NEC 334.10 and 334.12.


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## Southeast Power (Jan 18, 2009)

Ive seen plenty of commercial spaces wired with Romex.

Never done it myself but was up in the middle of Florida and, there it was...


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## donaldelectrician (Sep 30, 2010)

Arikculwell said:


> Well its connected to a commercial kirchen and offices so chief inspector said the units must be in mc aswell. But thanks.




MC in large numbers is a pain through Fire walls and electric rooms .


Plan ahead , EMT greatly cuts penetrations to be Fire Stopped .



Don


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## Arikculwell (Feb 16, 2016)

Got like 6 units in... My jman started talking to those air con people who seem to always be in my way and they said they was setting the dwelling as residental and the main hall/office/kitchen/dinning as commercail.......... cheif inspector... originally said that if dwellings reside under same roof then commercail rules apply under the entire roof... long story short my boss called him back and i guess its "okay" to run the dwellings in romex but, the entry door from hallway would be considered commercail so metal 3gang/mc/box. Now i know im just a lil over a year apprentice... but i enjoy the challenges of the trade. So can some one refer a code(section to read) where this is allowable?? As some one stated before its not what chief says its what nec says. Oklahoma goes by 2012.

Please, i dont need any comments like...
"Plan engineered approved??" I get paid by the hour, if builder wants to use my jman to make the plan so be it. Not my concern.


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## telsa (May 22, 2015)

In a, so-called, half-breed situation -- you must stay with the commercial standard all the way through the commercial space -- AND into the adjoining dwelling space -- until the first j-box, where it can transition to Romex.

I only ever had to wire once this way.

It was a PITA -- and a foolish idea -- as the dwelling space on that build was so tiny.

Whereas, your build would appear to make sense.


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## farmantenna (Nov 22, 2012)

using romex makes sense but you can still use romex in an offices . I've done it many times. Its not a place of assembly and the romex is covered behide 15min wall ceiling covering. I would say look at building types allowed for non metallic . we did a 55 unit assisted living and all the units were Romex with double 5/8 rock between unit and hall and had to use fire resistant putty pads on the boxes in that wall. halls and everything else was considered place of assembly since 100+ people could possibly be in the central dining living reading areas. we did a hotel rooms in Romex and everything else MC.  Here in New England most wood constructed buildings have 3/4" furring strips(strapping) running perpendicular to joists so you can staple to underside of joists. but most buildings without strapping have prefab trusses so you can go over the top of them if not an attic area


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