Burrito Q: Fastening of EMT

[Jim W in Tampa]

"Q 3. When EMT is installed within metal studs and it is not resting on the bottom of the opening, is additional support required?"

That was the question Mike answered. WITHIN METAL STUDS

 

[gadfly56]

I'm with Charlie - the "and" needs to be an "or" for the text to make sense.

I respectfully disagree. It is entirely possible to construct a scenario where the EMT is "securely fastened" and not "adequately supported". Lay 8' lengths of 1x2 between secure supports, wide edge up at 10' intervals. Lay some 2" EMT down the middle of this row of "supports". "Securely fasten" the EMT to the 1x2's. It wouldn't be hard to fill the EMT to just shy of the breaking point of the 1x2's. Now we're "securely fastened", but hardly "adequately supported". Now you may argue that this is a very artificial example, but in real life how many of us perform a load calculation to see if the supports will actually hold up the weight of our work? Darn few, I imagine, yours truly included. It's all rules of thumb and what's always worked before, and maybe add a little Kentucky windage if we're not sure.

 

[Jim W in Tampa]

"adequately supported"
Is not what it says. Remove adequately

Also we need to view the meaning of frameing members. A truss is made from framing members the same as walls are. The empty spaces are frame members.

 

[iwire]

Also we need to view the meaning of frameing members. A truss is made from framing members the same as walls are. The empty spaces are frame members.

Jim, we do not assemble trusses, when they arrive on the job site the truss is a framing member.

Again, look at the ROP I posted, they are very clearly talking about trusses.

 

[iwire]

Bob, no one is perfect, not you, not me, not the CMP and not Mr. Holt. We all make mistakes and in this case "they" are all wrong.

You are 100% correct about all of us making mistakes.

However in this case it is you that is mistaken, you are in great company but you are still with out the slightest bit of doubt in my mind mistaken.

Unfastened conduit in open trusses is most certainly subject to movement beyond what the couplings would safely withstand, from accidental contact, hanging loads, deliberate contact and possibly even seismic movement. Heck, in a long run even the forces of pulling in the conductors could cause couplings to separate if the conduit is not securely fastened.

And in the ROP the the CMP is looking for real evidence that is an actual problem not just a perceived one.

Lets go back to a 2x4 stud wall I run 1/2" EMT 50' horizontally through however many studs. In this case the holes are 1.25". Am I required to securely fasten the EMT every 10'? (Assume that it is securely fastened at the termination points)

Yes or No?

Simply lay one in the truss webs and secure the other at no more than 10' intervals as required by Code.

Pick any size and numbers of conductors to equal 75% fill.

Pull those conductors into each run and see what happens.

At the absolute minimum, I promise that the unsecured run will be moving around and making the pull harder, IF none of the couplings don't pull apart.

Of course it would move, you did not secure it within 3' of each termination.

But you also assume that just becuse it can move means it violates the code. That is a falsehood.

The 10' rule is there for a reason people. :grin:

There is no 10' rule for EMT horizontally run through framing member not matter how much that bothers you.

 

[iwire]

Regarding the CMP, if you are alluding to your post #48, nothing in that ROP gives us the CMP's opinion on this question. They rejected a proposal because it lacked technical substantiation. But they did not say whether the proposed idea had some merit, or no merit, and their response did not say anything at all about the need (or lack of need) to fasten EMT at 10 foot intervals.

Charlie ........ really ... I cannot fathom how you can posably say that.

Regarding Mike's published comment on this question, I disagree with his opinion. He would not object to people disagreeing with him, especially if they provide a technical basis for their own opinions. He is certainly welcome to disagree right back at me, as you are doing, and I respect all opinions.

That I agree with, Mikes opinion is just that an opinion.

Of course it is an opinion of a man that has been working exclusively with the NEC for many many years. Unlike the rest of us who the NEC is just a fraction of our job.

 

[Jim W in Tampa]

Jim, we do not assemble trusses, when they arrive on the job site the truss is a framing member.

Again, look at the ROP I posted, they are very clearly talking about trusses.

What does where they are assemled have to do with it. The air gaps are not part of anything.

As to the ROP it never said truss. What it did suggest is without straps conduit could be pushed out of the way. Now ain't that a real bright idea !!!!!!!! Great way to get them to pull out of couplings. Is this the same EMT we want as our ground ???

 

[iwire]

What does where they are assemled have to do with it. The air gaps are not part of anything.



As to the ROP it never said truss. What it did suggest is without straps conduit could be pushed out of the way. Now ain't that a real bright idea !!!!!!!! Great way to get them to pull out of couplings. Is this the same EMT we want as our ground ???

Jim arguing with you is pointless. Believe what you want.

 

[iwire]

I did read it and it said nothing about trusses.

Really try again with your glasses on.

Some openings may be more than 10 feet in width. I have seen several installations where the raceways looked like snakes between termination points in the roof trusses.

 

[mcclary's electrical]

:roll:

Jim arguing with you is pointless. Believe what you want.

Some men ,,,,you just can't reach

Plainly spoken English language isn't enough:roll:

 

[charlie b]

Charlie ........ really ... I cannot fathom how you can possibly say that.

Please take another look at your post #48. What you posted amounts to the following, and to nothing more than the following, with regard to the CMPs opinion on the present discussion.

• The submitter says, "I have an idea."
• The submitter then says, "Here is the reason for my idea."
• The CMP says, "We do not accept your suggestion."
• The CMP then says, "The reason we don't accept your suggestion is that you did not provide enough of a substantiation."

Where in that exchange can you possibly find a basis for concluding that the CMP has expressed their intent that fastening EMT as it passes through studs is not needed?

 

[iwire]

Please take another look at your post #48. What you posted amounts to the following, and to nothing more than the following, with regard to the CMPs opinion on the present discussion.

• The submitter says, "I have an idea."
• The submitter then says, "Here is the reason for my idea."
• The CMP says, "We do not accept your suggestion."
• The CMP then says, "The reason we don't accept your suggestion is that you did not provide enough of a substantiation."

Where in that exchange can you possibly find a basis for concluding that the CMP has expressed their intent that fastening EMT as it passes through studs is not needed?

If you can't see I certainly will not be able to make you see it.

To me it is as clear as day.

I also see very clearly B is 100% meaninless if you try to use it with A at the same time and that goes against any type of commonsense.

As you have said more than once. 'I will not agree to disagree as you are simply mistaken on this issue.'


To all ......

You guys do understand the NEC also allows EMT to be fished without any supports?

 

[iwire]

Where in that exchange can you possibly find a basis for concluding that the CMP has expressed their intent that fastening EMT as it passes through studs is not needed?

I can't help myself I have to try.:grin:

The fact the CMPs response was not 'That issue is already covered by A' (Or something along those lines) is to me the key.

 

[Jim W in Tampa]

"Workers installing other items or equipment can easily deflect the raceway either purposely or accidentally while doing their work. Painters or persons installing advertisements may disturb the electrical raceway position. "

That looks more like a reason to demand straps.
Flat out stupid to knowing allow your conduit to get moved out of there way.
Yes Bob it does say trusses.
Bottom line is what is in the code book is THE CODE. Like it or not they used the word AND not OR.

The burrito tasted great can i have another ?

 

[Jim W in Tampa]

"You guys do understand the NEC also allows EMT to be fished without any supports? "
I sure do, it says without COUPLINGS.

 

[Jim W in Tampa]

If you can't see I certainly will not be able to make you see it.

To me it is as clear as day.

I also see very clearly B is 100% meaninless if you try to use it with A at the same time and that goes against any type of commonsense.

As you have said more than once. 'I will not agree to disagree as you are simply mistaken on this issue.'


To all ......

You guys do understand the NEC also allows EMT to be fished without any supports?

We must use A with B because of the magic word AND

 

[charlie b]

The fact the CMPs response was not 'That issue is already covered by A' (Or something along those lines) is to me the key.

Sorry, but that's too much of a stretch for my tastes.

Looking at the most recent ROP, I see dozens (and I would see hundreds, if I had the free time to look) of examples in which the CMP said nothing more substantial than "you didn't prove your point, so we aren't going to enact your proposed change." In no case are they expressing an opinion on the merits of the proposed change. They are just laying the burden of proof on the submitter.

 

[charlie b]

We must use A with B because of the magic word AND

And to cap that off, A is about fastening, B is about supporting, and B has no words that undo any part of A.

 

[charlie b]

By the way, George, I have to infer that this thread was a failure. I suspect you were hoping to get enough of a consensus to impel one party to agree to buy the burrito for the other party. I don't think that happened.

 

[Jim W in Tampa]

And to cap that off, A is about fastening, B is about supporting, and B has no words that undo any part of A.

And we must do BOTH.