Running NMB under floor along a joist in old construction

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Old 09-21-16, 10:46 AM
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Question Running NMB under floor along a joist in old construction

How do you run NMB under floor along a joist in old construction?
 
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Old 09-21-16, 11:30 AM
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You staple it to the joist. Am I missing something?
 
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Old 09-21-16, 04:31 PM
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I can't rip up the entire floor.
 
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Old 09-21-16, 05:56 PM
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The cable must be fastened to the joist (or pass through a small hole in the joist) at intervals not exceeding 4-1/2 feetl and again within 12 inches of an outlet box or or panel box etc. it enters without a box clamp. However if it is necessary to rip open floor or ceiling or enlarge a fishing hole for the sole purpose of stapling the cable (or for drilling a passage hole in the joist not absolutely needed for the cable to get from point A to point B), then that staple/hole may be omitted/skipped/neglected.
 

Last edited by AllanJ; 09-21-16 at 06:45 PM.
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Old 09-21-16, 06:32 PM
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Fish tapes or rods help greatly . Can you access from below?
 
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Old 09-22-16, 08:43 AM
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From another post, I think this is a bonus room above a garage.
 
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Old 09-22-16, 09:03 AM
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Cables fished through finished spaces only need to be stapled where it is accessible. Otherwise you can use a fish tape or rods to get the cable through the closed bays with only limited disruption of the wall/ceiling finish material.

Note that because this is living space above a garage you are working with a rated fire wall, so make sure you're cognizant of that per your building code.
 
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Old 09-22-16, 09:04 AM
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Yeah its a bonus room, and builder only put one outlet....

Under the floor there are many nails and screws from the plywood underlayment and wood flooring.

Am I allowed to use, and leave in, a piece of UNSECURED conduit to protect the wire when fishing?
 
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Old 09-22-16, 02:09 PM
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If the nails are in the floor of the attic and you are fishing cables they will lay on the ceiling of the garage and the nails above are not an issue. How did you plan to get a conduit into a finished ceiling?
 
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Old 09-22-16, 02:26 PM
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I do not believe the code allows fished conduits; it only specifically mentions cables. An unsecured conduit could be more harmful to the wiring as the edges or fitting could abrade the insulation.
 
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Old 09-22-16, 02:45 PM
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What exactly are you trying do,do you have access to this,if joists are exposed you would staple the cables horizontally along them,or run a board perpendicular with them and staple the cable yo it.
How about some pics so we can see your situation.
 
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Old 09-22-16, 05:02 PM
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pcboss,

I probably didn't think things through.
 
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Old 09-22-16, 05:18 PM
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