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mdalli 06-29-2006 06:31 PM

Running Romex in the attic
 
I'm pulling Romex for a new circuit up from the garage (ground floor), up through the upstairs wall and up into the unfinished attic with 12" of blown insulation. No problem pulling the wires or installing the new circuits, but I have some questions once I get it into the attic.

Question #1: What is the preferred and legal way of running the Romex across the attic to where I'm going to install a utility/ light/ whole-house fan circuit (the fan will sit about center of the attic).

Question #2: As part of this circuit, I want to install simple incandescent light fixtures in the attic. I have two round octagonal boxes with the ceramic light bulb base, attached to the joists with a nail-on strap. Anything wrong with this?

A sincere thanks, in advance, for any help you can offer!

manhattan42 06-30-2006 08:45 AM

Quote:

Originally Posted by mdalli
I'm pulling Romex for a new circuit up from the garage (ground floor), up through the upstairs wall and up into the unfinished attic with 12" of blown insulation. No problem pulling the wires or installing the new circuits, but I have some questions once I get it into the attic.

Question #1: What is the preferred and legal way of running the Romex across the attic to where I'm going to install a utility/ light/ whole-house fan circuit (the fan will sit about center of the attic).

Question #2: As part of this circuit, I want to install simple incandescent light fixtures in the attic. I have two round octagonal boxes with the ceramic light bulb base, attached to the joists with a nail-on strap. Anything wrong with this?

A sincere thanks, in advance, for any help you can offer!

#1) The code compliant way is to run the cable through the joists or rafters or joists by boring through them with holes no larger than allowed by the construction code. Holes closer to the edge of a joist or rafter than 1 1/4" must be protected with nailing plates.

Cable run parallel to rafters or joists must be stapled at approved lengths and kept back from the edges of a joist or rafter by 1 1/4" or nailing plates will need to protect the cable.

You cannot run cable over the top of joists or fastened to the bottom of rafters.

If you have engineered wood products that make up the assembly of your roof, you should consult your code office and an engineer before boring or notching. Most engineered wood products cannot be notched or bored at all or can only be notched and bored at prescribed locations and only under the direction of an engineer.

#2) Should be ok.

IvoryRing 06-30-2006 10:12 AM

There are other methods allowed in an attic, in certain circumstances. You state that the attic is 'unfinished', but this doesn't really come into play. The real question is this: Does the attic have a stairway or permanent ladder to access it, or do you have to move a portable ladder into place in order to access it?

If you have permanent stairs or ladder, the attic is determined to be an 'accessable attic' (doesn't matter if you have a door, or a lock, or latch or anything else). In an accessable attic, you may run NM (NEC 334.23 for NM points to NEC 320.23 which is for AC) or AC across floor joists or anywhere else you like if it is protected by a guard strip at least as high as the cable itself. If you install it more than 7 ft above the floor or floor joists, you do not need a guard strip.

Without permanent stairs or a ladder, this is just an attic, in which case, the same protection is required within 6 ft of any scuttle hole (i.e. where you get into the attic by way of a portable ladder).

My understanding is that outside of the 6ft distance to the scuttle hole, the entire attic is considered to be space where you can fish cable how you like as long as it will not be placed within 1.25 inches of any outside surface.

The code uses the term guard strip, which I understand to be the same as 'running board', and that's exactly the method I used to get the bulk of my cables from one end of the attic to the other. In my case, I screwed a 8 inch wide running board the entire length of the attic, and stapled NM to this.

mdalli 06-30-2006 10:49 AM

It does not have, nor is likely to ever have, a permanent ladder or stairway. But basically, what you're saying is that there is a 6 ft radius "zone" around the scuttle hole (the hole the whole-house fan is going to be installed into, by the way) where I have to drill through floor joists or through rafters, right?

I always like to go beyond code, if possible. Would it be permissible to run the NM through holes in the floor joists (which are covered by insulation currently), stapling where the NM runs parallel to the joists?

IvoryRing 06-30-2006 12:00 PM

No - without a permanent ladder or stairs, the NM must be ONE of the following within 6 ft of the scuttle hole:

A.) bored through joist when run perpendicular
B.) stapled, etc when run parallel
C.) with a guard strip

i.e. you also have the option of the guard strip.

In all cases supported (at least) every 48 inches.

Without ladder/stairs, and outside of 6ft of the scuttle hole, it only needs to be placed such that a 1.25inch nail coming from outside the attic space (i.e. up through the ceiling below, or in from the roof above) will not have any way of touching it. NEC doesn't require you to protect for longer nails/screws,etc.

WITH a ladder/stairs, it must be supported the same way anywhere within 7ft of the floor.

If you wish to, there is nothing wrong with boring when going across joists and stapling when going with them, period.

If you really want to 'go above code', just install a raceway system in the attic... or EMT for all of it! Well, have to have deeper pockets then...

Out of curiousity... is your whole house fan going to block all/part of the scuttle hole so you can't get up into the attic if need be without removing it? (this isn't a code thing - I'm thinking about doing an attic fan myself)

mdalli 07-05-2006 12:14 PM

IvoryRing:"Out of curiousity... is your whole house fan going to block all/part of the scuttle hole so you can't get up into the attic if need be without removing it? (this isn't a code thing - I'm thinking about doing an attic fan myself)"

The fan blocks the entire scuttle hole. I have it secured in place with 3 screws that take about 30 seconds to remove when I need to go up there. BTW, whole-house fans are wonderful; great for either changing out the air in the house (e.g., clearing out smoke) or in the evening for drawing in cool air. Just make sure you don't go small on the fan -- get the biggest one possible that will fit.

I talked with WA state L&I, which takes code-related calls for an hour every weekday, about my situation. Here's what they told me:

It is perfectly acceptable to run the romex in the space between the ceiling joists, which is consider ample protection. They also told me that the exposed incandescent bulb setup is perfectly acceptable.

MrNoMaintenance 07-06-2006 01:51 AM

Another thought might be to run the wire in Ĺ inch metal conduit. The wire gets supported and guarded the entire length and Iíve also found that conduit in a home environment tends to impress local electrical inspectors too!! :)

Sparky Joe 07-06-2006 06:35 PM

About putting the fan in the access hole to your attic, if there are splices(j-boxes) in the attic, then they need to be accessible.


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