# Poll; Is This Code Compliant???



## 480sparky (Sep 20, 2007)

*300.4(E) Cables, Raceways, or Boxes Installed in or Under Roof Decking.* A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 38 mm (1½ in.) measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.

So, to answer your question, I'd say the _conduit _is legal, guessing there's 1½" clearance. The box, however, ain't.


Now, what about the unsupported pipes, and the pipe in front of the box?


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## erics37 (May 7, 2009)

Kinda wondering about the lack of supports within 3' of the box (or maybe even 5' per the exception?)


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## HARRY304E (Sep 15, 2010)

360max said:


> .
> 
> 
> 
> ...


344.30 Securing and Supporting. RMC shall be installed
as a complete system in accordance with 300.18 and shall
be securely fastened in place and supported in accordance
with 344.30(A) and (B).
(A) Securely Fastened. RMC shall be securely fastened
within 900 mm (3 ft) of each outlet box, junction box, device
box, cabinet, conduit body, or other conduit termination. Fastening
shall be permitted to be increased to a distance of 1.5 m
(5 ft) where structural members do not readily permit fastening
within 900 mm (3 ft). Where approved, conduit shall not
be required to be securely fastened within 900 mm (3 ft) of the
service head for above-the-roof termination of a mast.
(B) Supports. RMC shall be supported in accordance with
one of the following:
(1) Conduit shall be supported at intervals not exceeding
3 m (10 ft).
(2) The distance between supports for straight runs of conduit
shall be permitted in accordance with Table
344.30(B)(2), provided the conduit is made up with
threaded couplings and such supports prevent transmission
of stresses to termination where conduit is deflected
between supports.
(3) Exposed vertical risers from industrial machinery or
fixed equipment shall be permitted to be supported at
intervals not exceeding 6 m (20 ft) if the conduit is
made up with threaded couplings, the conduit is supported
and securely fastened at the top and bottom of
the riser, and no other means of intermediate support is
readily available.
(4) Horizontal runs of RMC supported by openings through
framing members at intervals not exceeding 3 m (10 ft)
and securely fastened within 900 mm (3 ft) of termination
points shall be permitted.


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## erics37 (May 7, 2009)

Pretty sure that's EMT there Harry.


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## 480sparky (Sep 20, 2007)

erics37 said:


> Pretty sure that's EMT there Harry.



That, or they can't thread rigid worth a darn. :laughing:


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## 360max (Jun 10, 2011)

480sparky said:


> *300.4(E) Cables, Raceways, or Boxes Installed in or Under Roof Decking.* A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than 38 mm (1½ in.) measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.
> 
> So, to answer your question, I'd say the _conduit _is legal, guessing there's 1½" clearance. The box, however, ain't.
> 
> ...


*
*


...I believe this is work in progress


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## 480sparky (Sep 20, 2007)

360max said:


> [/b]...I believe this is work in progress



I believe the box needs to move.


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## zwodubber (Feb 24, 2011)

Time to own up to my mistake 

OK, solution time. Don't have a book handy so bear with me. Could I reverse the six 3/4" offset pipes so the offset goes down. Remove the 1.25" pipes coming into the box and offset them below the decking thus lowering the box. This would leave the straight conduit run just above the decking but lowering the box below it.

And the support strut was removed this afternoon to work on leveling the box out. It is (was) going back up first thing tomorrow.


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## zwodubber (Feb 24, 2011)

Another view that might help with suggestions. 

Unless there is a violation in offsetting to lower a box below the roof decking that is the way I will go.


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## Executive (Aug 11, 2012)

Speak with your AJH. He may allow a protective steel plate above the box. Technically it is still a violation but owning up to your error and showing concern for the intent of the code article may sway him to let this one go with a solution that provides equivalent protection. It's worth a shot.

Chris


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## Hippie (May 12, 2011)

How is the box fastened up there? In this situation I would have spanned the top of the bar joists with strut and hung it from that, which would give plenty of clearance and also provide a means to drop a strut for strapping on the long sides


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## Bbsound (Dec 16, 2011)

It looks like you have plenty of clearance to me? Or am I seeing the picture wrong?


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## Big John (May 23, 2010)

Executive said:


> Speak with your AJH. He may allow a protective steel plate above the box. Technically it is still a violation...


 I was sort of surprised that they put in the exception for RMC but not for allowing protected enclosures.

-John


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## Bbsound (Dec 16, 2011)

zwodubber said:


> Another view that might help with suggestions.
> 
> Unless there is a violation in offsetting to lower a box below the roof decking that is the way I will go.


The "decking" is the corrugated metal pan. You are fine between the structural steel. 
You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems.


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## niteshift (Nov 21, 2007)

Bbsound said:


> The "decking" is the corrugated metal pan. You are fine between the structural steel.
> You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems.[/quote]
> 
> Yeah like 4" knarly f'n screws, they have no mercy, roofers push them thru blindly. Roof decking is alot thicker then EMT and j-boxes.


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## 360max (Jun 10, 2011)

Bbsound said:


> The "decking" is the corrugated metal pan. *You are fine between the structural steel. *
> You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems.


:no::no::no:

see the pic in post #1, box is to close to deck


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## 360max (Jun 10, 2011)

niteshift said:


> Bbsound said:
> 
> 
> > The "decking" is the corrugated metal pan. You are fine between the structural steel.
> ...


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## manchestersparky (Mar 25, 2007)

Quote:
Originally Posted by *Bbsound*  
_The "decking" is the corrugated metal pan. *You are fine between the structural steel. *
You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems._



360max said:


> :no::no::no:
> 
> see the pic in post #1, box is to close to deck







Read the Original post in the thread: 


*In the pic below, if the conduit was 6" off the ceiling but the box was touching the 'roof' deck, would this conduit run be code compliant?
*


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## zwodubber (Feb 24, 2011)

Bbsound said:


> The "decking" is the corrugated metal pan. You are fine between the structural steel.
> You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems.



OK, it was late last night and I was pretty tired and not processing the problem. For some reason I was interpreting decking as structural steel and I couldn't understand why people thought nails would hit it. That picture is deceiving as it does make it look close to the decking. There is easily 2-3 feet from the box to the decking. I thought everyone wanted it below the structural steel...


Had I known that I would have grabbed a pic today with a tape measure above the box. I did find another picture from yesterday with a better perspective.
Note the red circles are roofing nails, and unless they start using 2' nails I should be good.













On a side note the supporting strut is back in place


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## niteshift (Nov 21, 2007)

360max said:


> niteshift said:
> 
> 
> > I don't agree with that
> ...


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## Bbsound (Dec 16, 2011)

manchestersparky said:


> Quote:
> Originally Posted by *Bbsound*
> _The "decking" is the corrugated metal pan. *You are fine between the structural steel. *
> You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems._
> ...


:laughing: :tt2: :thumbsup: :jester:


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## Bbsound (Dec 16, 2011)

zwodubber said:


> OK, it was late last night and I was pretty tired and not processing the problem. For some reason I was interpreting decking as structural steel and I couldn't understand why people thought nails would hit it. That picture is deceiving as it does make it look close to the decking. There is easily 2-3 feet from the box to the decking. I thought everyone wanted it below the structural steel...
> 
> 
> Had I known that I would have grabbed a pic today with a tape measure above the box. I did find another picture from yesterday with a better perspective.
> ...


Hey, the job looks great to me!!


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## zwodubber (Feb 24, 2011)

I didn't even realize the original post implied my box was touching (or mounted to) the ceiling, man was I tired last night. Who would mount the box on the ceiling??

Monday will bring pictures with a tape measure for sure...


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## 360max (Jun 10, 2011)

manchestersparky said:


> Quote:
> Originally Posted by *Bbsound*
> _The "decking" is the corrugated metal pan. *You are fine between the structural steel. *
> You have to be below the decking so that mechanically fastened roofing system do not penetrate the raceways. They use long self drilling screws through the decking to hold down some roofing systems._
> ...


......it's not code compliant in the senario* I *created, read the relevant code article:


300.4(E) Cables, Raceways, or Boxes Installed in or Under Roof Decking. A cable, raceway,* or box,* installed in exposed or concealed locations* under metal-corrugated sheet roof decking,* shall be installed and supported so there is not less than 38 mm *(1½ in.)* measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.


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## 360max (Jun 10, 2011)

niteshift said:


> 360max said:
> 
> 
> > 360max, How do you fiqure corrugated metal roof decking is not thicker then EMT and/or j-boxes? :001_huh:
> ...


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## zwodubber (Feb 24, 2011)

360max said:


> ......it's not code compliant in the senario* I *created, read the relevant code article:
> 
> 
> 300.4(E) Cables, Raceways, or Boxes Installed in or Under Roof Decking. A cable, raceway,* or box,* installed in exposed or concealed locations* under metal-corrugated sheet roof decking,* shall be installed and supported so there is not less than 38 mm *(1½ in.)* measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.


The scenario you created almost had me redo my work. I will have to read threads thoroughly from now on.


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