Just recently I was asked to give a bid on a electrical upgrade for a house used as a summer residence. Upon inspecting the residence I find it is powered by knob n Tube which is to be removed and replaced with a modern system, now since this is house is all open framed inside re wiring the house with romex would be acceptable as long as all wiring follows all the framing members only, no running wires between studs or any open area's. Now I have been asking the local code inspector, and the senior code inspector aswell as my old school instructor if it is ok to use a metalic cable with a ground wire included with the other pre installed conductors inside , to be able to run this between studs and framing members and not have to just follow the framing members of the home, but, to just drill out holes and run between the studs and such, While they are searching the code books for an answer I was currious if anybody new off hand the answer to this?
FWIW, arguments regarding AC(BX)/MC vs NMC in structures that are to remain 'open framing' (no wallboard) have abounded for many, many years, and varied by jurisdiction.
Looking from a practical standpoint (common sense) AC/MC can be damaged (outer jacket) between studs easier than NM. We all know that AC crimps, or 'spirals' under stress. The argument was 'storing' things (shovels, brooms, etc.) in the cavity between the studs, using the wiring that happened to be there for support of the item.
The debate may arise IF this summer home could be considered a damp location by the local AHJ. My suggestion is to speak to the local AHJ before you get into this project.
The term 'subject to physical damage' varies by interpertation!
Yes, you can damage NM, but the concensus was...not as easily.
We (NJ) had a directive (FTO)from state that NM was not approved within an open framed structure. That directive was rescinded about 3 years back. With a freesta nding resi garage, it wasn't uncommon for an owner to say the walls will be finished, and that not happening.
Smurf tube is also a fairly tough material but it still has the "physical damage" thing. You could always pretend like you were in Chicago and pipe the whole place with EMT.
It may end up being faster to just do all the runs down from the top and do your horizontal runs in the attic or right up against the top plate in the wall. If you still want added protection you can sleeve the vertical runs in pipe.