NM above dropped ceiling

[johnny watt]

334.12 Uses Not Permitted.
(A) Types NM, NMC, and NMS. Types NM, NMC, and NMS cables shall not be permitted as follows:
(1) In any dwelling or structure not specifically permitted in 334.10(1), (2), and (3)
(2) Exposed in dropped or suspended ceilings in other than one- and two-family and multifamily dwellings

I have heard it argued that the space above the lag screws that the grid is hung from is not ?in? the dropped ceiling and therefore NM cable can be used. More specifically the ceiling is hung from the bottom chord of the truss so NM cable is permitted above the bottom chord.

Anyone heard of this interpretation before?

 

[websparky]

I have heard the argument before! But then I remind them of 334.10(3):

Other structures permitted to be of Types III, IV, and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of firerated assemblies.

and ask them if they can satisfy that requirement!

 

[bphgravity]

I agree with Dave. A typical drop ceiling is NOT a fire rated assembly and will not provide the 15 minute rating. And be aware that a flame spread index has no correlation to this requirement.

 

[jwelectric]

My answer is the same as was given elsewhere in cyberspace.
No matter neither how many you ask nor how many different places the correct answer will always be the same. NO! NO! NO!

 

[iwire]

NO! NO! NO!

So is it OK or not?