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-   -   Running wire in unifinished attic in detached garage (https://www.askmehelpdesk.com/showthread.php?t=380209)

  • Jul 26, 2009, 08:23 PM
    trying2hard
    Running wire in unifinished attic in detached garage
    Hi Folks,

    I've read that electrical code allows you to run romex (14/2 or 14/3) perpendicular and on top of the ceiling joists, but only if the wires are protected by a 'guard strip' that is at least as wide as the wire. I'd like to clarify what this means? Does this mean that the wire needs to run in a channel created by the guard strips, or just on top of the guard strip?

    I had a plan for my unfinished garage attic (no permanent access), but I'm not sure if it is to code. I was planning to staple one or two 14/2 romex runs on top of a 1x4 brace that is nailed to the top of the ceiling joists near the middle of the joist span. Is this to code?

    If this won't fly, and I decided to use plastic/pvc conduit for these runs, could I just rip the romex I planned to use and run the individual wires from the romex through the conduit?

    Thanks!
  • Jul 26, 2009, 10:08 PM
    hkstroud

    "Where this space is not accessible by permanent stairs or ladders, protection shall only be required within 6 feet (1.83 m) of the nearest edge of the scuttle hole or attic entrance."
  • Jul 27, 2009, 06:01 AM
    trying2hard
    Quote:

    Originally Posted by hkstroud View Post
    "Where this space is not accessible by permanent stairs or ladders, protection shall only be required within 6 feet (1.83 m) of the nearest edge of the scuttle hole or attic entrance."

    Thanks for your response! But perhaps I didn't make myself clear... in fact I know I didn't - I forgot one detail. This is an unfinished garage and there is no ceiling, just joists. So am I to assume that by code there is an attic entrance between each joist, which means that the entire attic space needs to be protected? Or that there is no attic entrance which means that the entire attic space needs no protection.

    Further to the point, my question was about the 'protection' itself, and what exactly that means? Do I make a channel with furring strips, or is it sufficient to staple wire on top of a 1x4 horizontal brace?

    Thanks!
  • Jul 27, 2009, 06:51 AM
    hkstroud

    Look at the rest of the code, the part about being 7 feet from floor. Note that the wording says "as high" as the cable" not as "wide". My interperetation is that the protection must be a installed along side of the wiring. In other words, nail up some furring strips and put you wiring next to the edge of it (stapled to the joist). Just so you can't step on the wiring between joist or store your left over building material on it. Code doesn't seem to say how close it has to be. Code doesn't say it has to be in a "channel", I think you are trying to hard.

    One interpertation could be that you don't have an attic until you put in a ceiling, just joist running across the garage. A 1x4 across the joist takes care of it, no mater what the interpertation.
  • Jul 27, 2009, 08:49 AM
    tkrussell

    Stupid question, but why not just drill through the joists and pass the cable through these holes?

    No protection is needed then.
  • Jul 29, 2009, 03:19 AM
    trying2hard
    Quote:

    Originally Posted by hkstroud View Post
    Look at the rest of the code, the part about being 7 feet from floor. Note that the wording says "as high" as the cable" not as "wide". My interperetation is that the protection must be a installed along side of the wiring. In other words, nail up some furring strips and put you wiring next to the edge of it (stapled to the joist). Just so you can't step on the wiring between joist or store your left over building material on it. Code doesn't seem to say how close it has to be. Code doesn't say it has to be in a "channel", I think you are trying to hard.

    One interpertation could be that you don't have an attic until you put in a ceiling, just joist running across the garage. A 1x4 across the joist takes care of it, no mater what the interpertation.

    Thanks, I guess when I said 'channel' I was trying to refer to exactly what you described. I was trying 2 hard. :)
  • Jul 29, 2009, 03:24 AM
    trying2hard
    Quote:

    Originally Posted by tkrussell View Post
    Stupid question, but why not just drill thru the joists and pass the cable thru these holes?

    No protection is needed then.

    I suppose that would work. But this is in the middle of the joists. I wanted to run wire for a lighting circuit down the middle of the structure. I see an exposed wire pulled through joists in the middle of a structure as a potential hazard in an unfinished ceiling? I could be lifting a ladder through the spaces between the joists and catch the wires or something... This might be fine if done closer to the walls though...

    Also, is it okay to drill through joists in the middle 1/3 of the span? I thought that was a no-no?
  • Jul 29, 2009, 03:49 AM
    tkrussell
    Correct,

    Quote:

    Originally Posted by trying2hard View Post
    Also, is it okay to drill through joists in the middle 1/3 of the span? I thought that was a no-no?


    No drilling holes in the center one third of a joist.

    Keep the holes in the one third close to the wall, then staple on the face of the joist to get to the lighting outlets in the center of the span.
  • Jul 29, 2009, 02:14 PM
    pelle

    TK
    What about drilling trusses I thought you could not do that. If this is the case are we talking about joists or the bottom of a roof truss.
    Thanks in advance.
  • Jul 29, 2009, 04:43 PM
    tkrussell
    Very good point,

    Quote:

    Originally Posted by pelle View Post
    TK
    What about drilling trusses I thought you could not do that. If this is the case are we talking about joists or the bottom of a roof truss.
    Thanks in advance.


    Never, never, never, drill through trusses.


    All I went on is ceiling joists mentioned and assuming here is plenty of room in the attic, without the obstructions of the truss cross members.
  • Jul 29, 2009, 07:38 PM
    trying2hard
    Quote:

    Originally Posted by tkrussell View Post
    Very good point,




    Never, never, never, drill thru trusses.


    All I went on is ceiling joists mentioned and assuming here is plenty of room in the attic, without the obstructions of the truss cross members.

    Okay, now I'm confused. :) And I'm probably going to show my inexperience as I step back to clarify things... I built a garage (with lots of help!) using engineered rafters, which come pre-built in the shape of a triangle with a vertical support member from the middle of the bottom member to the rafter ridge. The bottom member of these rafters is sitting horizontally across the width of the structure on the top plate of my walls. Rightly or wrongly, this bottom member of the rafter is what I referred to as a ceiling joist. Are you saying that I cannot drill through the bottom member without weakening the structure? Or are you referring to the vertical member as the truss? I do not intend to drill through the vertical support.

    Thanks again!
  • Jul 30, 2009, 04:54 AM
    tkrussell
    Good thing someone mentioned pre-enginerred truss.

    Since you said joist, I did not think of truss.

    Disregard my mention of drilling.

    No member of any pre-engineered truss system can be drilled, unless designed for that, which most are not.

    I suspect these are 24 inch on center. Laying cable on top will be a bit messy if you don't stretch out and staple.

    I would still lay cable close to the wall, stretch the cables taut and staple to the top of the truss "joist", and not worry about any firring strips or runners for protection, in this case.

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