Need opinions here:
We are having a new Fire Alarm installed in one of our buildings. Some of the new Fire Alarm EMT is installed above the bar joists, tight to the roof deck. We're on 2008. I've been thru 760 several times and can find no ref to 300.4. Therefore I need opinions:
Based on this section
760.3 Other Articles. Circuits and equipment shall comply
with 760.3(A) through (G). Only those sections of Article
300 referenced in this article shall apply to fire alarm
systems.
Does this section apply?
(E) Cables and Raceways Installed Under Roof Decking.
A cable- or raceway-type wiring method, installed in
exposed or concealed locations under metal-corrugated sheet
roof decking, shall be installed and supported so the nearest
outside surface of the cable or raceway is not less than
38 mm (11⁄2 in.) from the nearest surface of the roof decking.

Steve:

I feel your pain after a quick read. Although 300.4 SHOULD apply, there is no written word that I see.

IMHO, I would have a man to man with the installer, explaining the theory behind 300.4, and ask for voluntary compliance.

This is one of the 'holes' that needs to be plugged. Thank you for pointing this out.

I'm hoping the AHJ will enforce 300.4. My installer already told me no way.

IF your installer is really 'code savy', he may take the stand that 300.4 does not apply, based on 760.

Between a rock & a hard place.

And what of the Exclusion for EMT RMC IMC ?

Tesla:

Where are you referencing your exclusion??

RMC/IMC are allowed in 300.4(E)

AND EMT...

So no problem...

Get it?

So the installer 'wins' the argument.

Tesla:

Am I missing something? Where is EMT mentioned?

From 2011 NEC 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 (11⁄2 in.) measured from the lowest
surface of the roof decking to the top of the cable, raceway,
or box. A cable, raceway, or box shall not be installed in
concealed locations in metal-corrugated, sheet decking–
type roof.
Informational Note: Roof decking material is often repaired
or replaced after the initial raceway or cabling and
roofing installation and may be penetrated by the screws or
other mechanical devices designed to provide “hold down”
strength of the waterproof membrane or roof insulating
material.
Exception: Rigid metal conduit and intermediate metal
conduit shall not be required to comply with 300.4(E).