518-4 says that non metalic raceways shall be encased in 2" of concrete. Other than under a concrete slab, can you give an example of an installation that would include a 2" concrete envelope around the conduit?
Is the code refering to non metalic conduit runs outside of the building that feed or support places of assembly?

Encased would mean surrounded by concrete.

I had to change a word from conduit to concrete.

[This message has been edited by russ m (edited 01-28-2004).]

The code is saying if you use non metalic raceway it has to be surounded by concrete, unless it is allowed in (B) or (C)

Thanks for your replys.
So in the exception you can install PVC in a conferance and meeting room but not a Multipurpose room because a multipurpose room is an area listed as a place of assembly not included in the exception.
What does not make sense about that interpretation is that many of the rooms not listed in the exception are interchangeable with the rooms listed in the exception.

Here is the origin of my interest in this subject. A structural engineer stated that a 3/4" PVC conduit installed in a structural concrete deck had to be spaced 2” from the face of the finished concrete. He sighted NEC 518-4 as the reason for the requirement. The structural deck is in between a parking level below and meeting rooms above.