I have a question on conduit in concrete. Under definition's of "location wet" Installations in concrete slabs are considered a wet location. Does the slab have to be in direct contact with the earth. Is it only called a "slab" if it in direct contact with the earth. If there is concrete on the fourth floor would it be considered a wet location. The conductors are not a concern as most are dual rated. I ask this because for years it has been debated in my code classes. Many say the concrete is wet when poured and that it retains moisture. I say that emt set screw type fittings are listed as concrete tight and are not water tight. I think that there are to many "or's" in the definition. What do you say?