300.4

[panhandle444]

300.4 (E) requires a minimum of 1.5 inches clear space between the metal corrugated sheet roof decking and the outer surface of the metal-clad cable.

What if the MC cable is supported against the metal truss that the corrugated roof is mounted to? The metal truss is probably 1/8 or more steel. It just so happens the MC will be in the 1.5 inches of the corrugated roof

 

[ActionDave]

Can't do it. You need to be an inch and a half below the lowest part of the roof deck, that means you need to be an inch and a half below the part of the corrugation that sits on the roof truss.

 

[panhandle444]

Can't do it. You need to be an inch and a half below the lowest part of the roof deck, that means you need to be an inch and a half below the part of the corrugation that sits on the roof truss.

So having an MC supported as such would be wrong?

 

[GoldDigger]

I would have to say technically yes.
There does not appear to be any exemption for MC protected by a barrier, even though the beam is thicker than the most aggressive nail plate made.

 

[infinity]

So having an MC supported as such would be wrong?

If that reddish steel were 1.5" inches you would need to be on the underside of it to comply with 300.4. RMC or IMC would be permitted to be less than 1.5" below the decking even though they're significantly thinner than the steel in the photo.

 

[iwire]

So having an MC supported as such would be wrong?

Yes, move to the bottom chord of the truss.

I would have to say technically yes.
There does not appear to be any exemption for MC protected by a barrier, even though the beam is thicker than the most aggressive nail plate made.

But the 'tek' screws the roofer uses can penetrate the truss.

 

[GoldDigger]

I think the OP is calling the metal extrusion you see in the picture a truss, in which case there may be no ,"bottom chord"

mobile

 

[ActionDave]

I think the OP is calling the metal extrusion you see in the picture a truss, in which case there may be no ,"bottom chord"

mobile

That is the top chord of a metal truss or bar joist.

 

[iwire]

I think the OP is calling the metal extrusion you see in the picture a truss, in which case there may be no ,"bottom chord"

I guess the proper term I should have used was 'bar joist' but it will have a bottom.

 

[jumper]

If the OP really wants to up there, vertical bang on caddy clips could be an option.

Should make 1 1/5" off the bottom of the angle iron to the deck/roof.


http://www.gordonelectricsupply.com...ocess~search?gclid=CKXTz4O26tECFYeFswod2EwNgA

 

[ActionDave]

If the OP really wants to up there, vertical bang on caddy clips could be an option.

Should make 1 1/5" off the bottom of the angle iron to the deck/roof.


http://www.gordonelectricsupply.com...ocess~search?gclid=CKXTz4O26tECFYeFswod2EwNgA

True. I've done that before. The clips cost more than zip ties but they are quicker to use.