Bar joists

[Hendrix]

Anywhere in NEC that would prohibit securing EMT to them?

 

[steve66]

I think not. They would be considered part of the building structure, and fair game.

Otherwise, there are a lot of violations around.

Steve

 

[Hendrix]

Thanks Steve, I do remember a building inspector prohibiting that, but I guess it was a local thing.

 

[iwire]

Many times we are not allowed to secure anything from the bottom chord of bar joists. This is a building code / manufacturers thing.

 

[Hendrix]

Many times we are not allowed to secure anything from the bottom chord of bar joists. This is a building code / manufacturers thing.

I just asked the building inspector and he is OK with it. Thanks for the reply.

 

[tkb]

You can't run conduits or cable on top of the bar joists in the deck webbing anymore.

 

[masterinbama]

You can't run conduits or cable on top of the bar joists in the deck webbing anymore.

Only if it's roof decking. Floor decking is okay but most of it's not deep enough to use.

 

[tkb]

Only if it's roof decking. Floor decking is okay but most of it's not deep enough to use.

True. :grin:

 

[ZinskI/E]

You can't run conduits or cable on top of the bar joists in the deck webbing anymore.

It's been awhile since I've worked in a building with webbed decking. When did this change and what's the code reference?

I remember back in 2001 we had a building with joists 9'-6" apart and we could cut bundles of conduit down by 8" and run a hundred feet without ever having to move the ladder.

 

[rcarroll]

it's been awhile since i've worked in a building with webbed decking. When did this change and what's the code reference?

'08 nec 300.4(e)

 

[ZinskI/E]

'08 nec 300.4(e)

Thanks.

 

[gadfly56]

You can't run conduits or cable on top of the bar joists in the deck webbing anymore.

Do you mean above the top chord of the bar joist (in the deck "waffle") or in the space between the top and bottom chords?

 

[ZinskI/E]

Do you mean above the top chord of the bar joist (in the deck "waffle") or in the space between the top and bottom chords?

According to 300.4(e) (thanks again to rcarroll) you can only run in the "waffle" if there is at least 1 1/2" of clearance from the decking to the EMT or cable, and I haven't seen many corrugated decks with that much clearance. Between the top and bottom chords is still acceptable.

 

[jusme123]

According to 300.4(e) (thanks again to rcarroll) you can only run in the "waffle" if there is at least 1 1/2" of clearance from the decking to the EMT or cable, and I haven't seen many corrugated decks with that much clearance. Between the top and bottom chords is still acceptable.

Yes you are allowed to run conduit in the 'waffle' (area directly under roof decking) BUT it has to be rigid or intermediate metal conduit see 300.4 (E)(exception)