Accessable attic & Junction boxes (NEC question)

IvoryRing

This is more a 'code compliance' question than it is a 'will this work' question...

If I understand NEC correctly, when an attic is considered accessable, the rules for running romex are more strict than if it is not considered accessable. The defining difference between the two seems to be this: if there are stairs or a permanent ladder, then it is accessable.

What is the intersection between this and the requirement that all junction boxes be accessable (i.e. can't be drywalled over, f.e.)? If I have neither stairs nor a permanently installed ladder, does this mean I can't have any junction boxes in the attic at all?

Speedy Petey

Where do you find this??? I know of no such thing.

Not true.

NEC definition:
Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building.


See definition of accessible.

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

IvoryRing

In 334, which defines/describes NM cable:

334.23 In Accessible Attics. The installation of cable in accessable attics or roof spaces shall also comply with 320.23

So, in an accessable attic, NM has to be installed with the same constraints as AC.

320.23 says (paraphrasing) that all cable within 7 ft of the floor must be protected by substantial guard strips or be supported parallel to framing members throughout the entire attic, unless there is no permanent ladder or stairs, in which case the protection is required only within 6 ft of the attic access hole.

It looks to me like this is related in some way to the definition 'Accessible, Readily' in section 100, v.s. 'Accessible (as applied to wiring methods)', since there is a reference to requiring access to portable ladder, height, etc - not talking about 'damaging finsh/structure/permanantly closed in'.

So, if I'm understandly all this correctly - without a permanent ladder, the attic is not considered readily accessible, so supporting the romex perpendicular rafters, etc, is fine as long as it is more than 6ft from the access hole. The question I have is if this conflicts with wherever it says (and I don't know where it actually says that!) that junction boxes have to be accessible.

Speedy Petey

I think you are confusing the boxes being accessible and an accessible attic. Two different things entirely.

The only thing 320.23 say is that in an accessible attic the cables must be protected within 7' of a ladder or stairs, or within 6' of a scuttle hole. Thats it.
It is not saying one is considered accessible and one is not.
Re-read the exact text:

(A) Where Run Across the Top of Floor Joists Where run across the top of floor joists, or within 2.1 m (7 ft) of floor or floor joists across the face of rafters or studding, in attics and roof spaces that are accessible, the cable shall be protected by substantial guard strips that are at least as high as the cable. Where this space is not accessible by permanent stairs or ladders, protection shall only be required within 1.8 m (6 ft) of the nearest edge of the scuttle hole or attic entrance.

See, it say where not accessible BY permanent stairs or ladders. Meaning a scuttle hole.
Both are accessible attics, just accessible by different means.

Also, there is no mention of junction boxes. Only cable protection.

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

djake11

A) Where Run Across the Top of Floor Joists Where run across the top of floor joists, or within 2.1 m (7 ft) of floor or floor joists across the face of rafters or studding, in attics and roof spaces that are accessible, the cable shall be protected by substantial guard strips that are at least as high as the cable. Where this space is not accessible by permanent stairs or ladders, protection shall only be required within 1.8 m (6 ft) of the nearest edge of the scuttle hole or attic entrance.

The language confuses me. I'm having a hard time visualizing the framing configuration that is described. There are no "floor joists" unless they are covered with decking. If there is decking, then the cable would be run over the decking, not the joists. There may be problems with framing terminology.Can somebody help unscramble me?

dudleydoright

One mans ceiling joist is another mans floor joist. It is only a ceiling joist until you are on top of it moving then it magically transforms into a floor joist. Until you exit the attic that is, unless you install permanent travel boards, then I guess that those crawl boards would make them
perm
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Speedy Petey

From 2006, to 2011, to today. Seriously???

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.

electures

Holy thread revival Batman!!

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All responses based on the 2011 NEC.
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