I am asking in reference to articles 382.2 & 382.12 in the 2008 edition of NFPA-70.

The following definition appears to me to be describing Romex (NM-type) cabling:

**382.2 Definitions**
**Nonmetallic Extension.** An assembly of two insulated conductors within a nonmetallic 
jacket or an extruded thermoplastic covering. The classification includes surface 
extensions intended for mounting directly on the surface of walls or ceilings.

Then, this article indicates that nonmetallic extensions cannot be used in attics:

**382.12 Uses Not Permitted.** Nonmetallic extensions shall not be used as follows:
***(1) In unfinished basements, attics, or roof spaces***
(2) Where the voltage between conductors exceeds 150 volts for nonmetallic surface
    extensions and 300 volts for aerial cable
(3) Where subject to corrosive vapors (4) Where run through a floor or partition, or 
    outside the room in which it originates

My home is a single-family dwelling with a single floor, an unfinished accessible attic (permanent ladder) with crawl space only, and an unfinished basement.

I was hoping to be able to use Romex to connect branch circuit junction boxes in my attic with runs along the floor joists and through the floor joists (existing bored holes from knob and tube). I was also hoping to be able to use Romex with runs along the ceiling joists and through the ceiling joists in sections of my unfinished basement to connect junctions and light fixtures. However, these articles appear to prohibit the use of Romex in unfinished attics and basements. Must I use MC or AC for this application or am I misinterpreting the definition of a nonmetallic extension? Or, is there an article that I am missing that makes plain Romex acceptable for these applications?

Also, if it is not acceptable for these applications, how should I deal with getting runs of Romex down from the attic (or up from the basement) to power receptacles in the finished portion of my home? Is there an acceptable defined length for which NM cabling may be run in the attic to reach from a junction in an unfinished attic to power a wall receptacle, or is the only way to be code-compliant to just run AC down to the first (metal) receptacle junction box and run Romex through the walls to the other wall receptacles in the room?

1 Answer 1


You're referencing the wrong code section.

Nonmetallic-Sheathed Cable

Romex is covered by article 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS.

NM Cable Assembly

Nonmetallic Extensions

Article 382 covers a cable known as FlatWire, or Concealable Nonmetallic Extension (CNE) cable.


Notice that this cable has a single insulation layer over the conductors. Whereas NM cable has insulation on the conductors, and an outer insulated sheath.

  • Thank you for the clarification. I just happened upon section 334 as you posted and was going to update my question regarding section: "334.23 In Accessible Attics. The installation of cable in accessible attics or roof spaces shall also comply with 320.23" (an article on routing AC in attics). Does this imply that only armored cabling may be used for this purpose or is it simply referring me to use the same techniques for securing NM cabling as is used for AC?
    – user14416
    Aug 7, 2013 at 16:19
  • It just means that you have to follow the wiring methods described in 320.23(A) and (B).
    – Tester101
    Aug 7, 2013 at 16:42

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