Attic wiring-Adding flooring

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Is it OK to drill round holes in the flooring where house wiring crosses the joists so that there is no pressure on the wires at those points? Between the joists the wires would be pushed slightly below the flooring. Thank you for advice.
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On 5/31/2014 10:03 AM, snipped-for-privacy@yahoo.com wrote:

NO. cutting a notch or drilling a hole like that will weaker the structure. Holes should be drilled through as close to the center as possible.
If you have 2 x 8 beams and cut a 2" groove, you now have about the strength of a 2 x 6. I think you'll find that a code violation too.
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On Saturday, May 31, 2014 11:03:41 AM UTC-4, Ed Pawlowski wrote:

I agree with the general premise. But it sounds like what he's talking about is the thickness of a Romex, eg 1/4", not taking 2" out of a joist. If that's all there is and he covers it with a metal strike plate, I could live with it. Or if there are a lot of instances like this, he could nail some strips to the joists to raise the flooring by 1 1/2, then nail flooring to that. Maybe a lot higher than that, if it's in a cold/hot climate where you need more insulation than you're going to get in just a joist height thickeness.
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On Saturday, May 31, 2014 11:18:26 AM UTC-4, trader_4 wrote:

I had the same issue many years ago. Cutting just a little from the top of the joist weakens it greatly. And a strike plate wouldnt help much:(
Much better to add ome stapping and put the plywood deck over that....
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On Saturday, May 31, 2014 11:34:03 AM UTC-4, bob haller wrote:

Sure if you make a notch for a drain pipe. But for the thickness of a Romex cable?
Within the outer third of the span, on either end, per code you can notch out 1/6th of the whole joist. If 1/6th doesn't screw it there, it's hard to imagine 1/4" causing a failure anywhere. And the preferred location is the top versus the bottom. The metal strike plate is to prevent nails from being driven in, has nothing to do with strength.

Even if there are just two places where a romex goes over a joist in the whole attic? You'd still attach wood strips all over the whole attic to raise it all up?
Me, I'd make the 1/4" notch and sleep well at night.
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On Saturday, May 31, 2014 10:03:38 AM UTC-4, snipped-for-privacy@yahoo.com wrote:

add some wood laid FLAT and then screw your decking to that added wood. Mind where the wires are so you DONT screw into them!
DONT NOTCH THE JOISTS
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On Sat, 31 May 2014 08:18:26 -0700 (PDT), trader_4

You're both wrong. He asked about cutting holes in the flooring, not the joists.
Your plans are better.

That's true. Even in a temperate climate like Baltimore I gather he should consider adding more insulation and how to make room for it.
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On Saturday, May 31, 2014 12:09:58 PM UTC-4, micky wrote:

You're right. That's what he said, but mentally I pictured it the other way around. I just checked code and it looks like you can make a notch up to 1/6 of the joist as long as it's within 1/3 of the span on either end. If it's in the middle third, you're not supposed to make any notch. But I could certainly live with 1/4" and sleep at night.
But if it is in the center 1/3, and he doesn't want to make a small notch, then he could do what he stated, ie cut a hole in the flooring so that it fits around the cable. I would then fasten a metal strike plate on the top to cover and protect it.

Yes, I'd definitely take insulation into account before doing anything.
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On 5/31/2014 12:09 PM, micky wrote:

Yeah, I read it backwards. Depending on a few factors, I may or may not cut the flooring. Behind furniture, probably not a big deal. In a high traffic area. anything could happen.
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*I don't fully understand what you are doing, but the electrical code requires a minimum of 1.25" set back for any wiring in a stud or joist to prevent nails and screws from coming in contact. Anything less requires a small steel plate to prevent nails and screws from penetrating the wire.
If you are proposing to put a floor down on top of joists that have wires running across them, I would not recommend that. There is too much of a risk of the wire or insulation being pinched. In a situation like that, the problem may not manifest itself for several years at which point arcing may occur in close contact with a combustible material. This is how electrical fires start.
I spend a lot of time in attics and have seen situations where homeowners have laid plywood right on top of wires that cross joists. After years of shuffling boxes and walking, the insulation on the wires starts to wear down. In a best case scenario, the circuit breaker trips. In a worst case situation a fire starts. Up in the attic no one is around to smell something burning until it too late.
Either relocate the wires properly or lay down 2"x2" strips to get good clearance.
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On Saturday, May 31, 2014 10:03:38 AM UTC-4, snipped-for-privacy@yahoo.com wrote:

Thanks to all, but only Micky seems to understand my intentions. I planned to have Home Depot cut a bunch of 4x8's in half to make 4x4's. Then I will assemble the smaller pieces (much easier to get them up into th e attic) into a tile-like arrangement with each piece straddling 3 joists w hich, by the way are 2x6's. Any place that a 'tile' covers a wire I will m ark it and cut out a hole with approximately a 3" diameter. Just enough to expose the width of the joist including a little extra space for the NM cab le to enter the hole on one side of the joist, go over the width of the joi st and go back down into the hole on the other side of the joist. Does anyone think this might work and might be compliant with NEC? It seems to me that it is equivalent to running wood strips across all the joists and then fastening the flooring to those strips.
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On 5/31/2014 8:38 PM, snipped-for-privacy@yahoo.com wrote:

If I understand this correctly, you will have a thru hole and an exposed wire in the hole. If that is correct, it is a half assed solution, does not meet code, and a potential danger.
I hope I'm wrong. Strapping seems to be the proper solution.
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Let me try to translate....

4x4[SHEETS OF PLYWOOD].

PLYWOOD] straddling 3 joists which, by the way are 2x6's. Any place that a [4X4 SHEET OF PLYWOOD] covers a wire I will mark it and cut out a hole [i n SHEET OF PLYWOOD]with approximately a 3" diameter. Just enough to expose the width of the joist including a little extra space for the NM cable to e nter the hole [in SHEET OF PLYWOOD]on one side of the joist, go over the wi dth of the joist and go back down into the hole [in SHEET OF PLYWOOD]on the other side of the joist.

Is this what youare trying to do?
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On Saturday, May 31, 2014 10:03:38 AM UTC-4, snipped-for-privacy@yahoo.com wrote:

I might also install protective metal plates over each of the holes. Not only does this prevent accidental damage to the wiring but it also locates all the wiring on the floor of the attic. I would fasten both the 4x4's and the metal plates with screws for easy access.
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From an engineering viewpoint, if you have to drill holes through a joist, the location of the hole that would least weaken the joist would be half way up the joist or higher as close to either end of the joist as possible.
--
nestork

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On Sat, 31 May 2014 07:03:38 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

Aither drill the joists or strap the floor with minimum 2 inch strapping to space the floor above the wiring, which would then need to be strapped to the joists.
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On Saturday, May 31, 2014 9:41:28 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:

IDK where that is coming from. You can't get 2" inside typical interior 2x4 framed walls because the it's only 3 1/2 inches wide.

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On Sat, 31 May 2014 17:38:48 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

flat .
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On Sat, 31 May 2014 17:44:28 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

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On Saturday, May 31, 2014 9:47:08 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:

I'm not so sure about that. You have a cite? Provided he cuts holes in the plywood where the wire crosses joists and then covers it with a metal protective plate, it would seem to me that the cable is suitably protected. It's not exposed in any way. How would the cable ever be subject to damage? You can run it exposed along the side of a guard strip, so what's the problem with having it covered by plywood and metal plate?
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