Need quick answer: 344.10(B)(1)

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charlie b

charlie b

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Short version of question: Can galvanized rigid steel be direct-buried in the dirt below the bottom slab of a building, without having any corrosive protection (such as PVC coating) added?

Longer version: Which of the following does 344.10(B)(1) mean?
  1. OK in concrete. OK in dirt. OK in corrosive area, but only if protected against corrosion.
  2. OK in concrete, but only if protected against corrosion. OK in dirt, but only if protected against corrosion. OK in corrosive area, but only if protected against corrosion.
In other words, does the phrase ". . . where protected by . . . " apply to all three areas (concrete, dirt, and corrosive environment), or just to the third one (corrosive environment)?
 
this isnt an answer

this isnt an answer

some manufacturers claim there GRC is hot dipped and top coated to be extra corrosion resistant. (allied) I would think that unless something weird came up on the soil boring report standard practice would be acceptable. Unless this is brownfield work. I am curious to hear others chime in.
I read it as 1.
 
I would say #1, can be buried in dirt or embedded in concrete, without further protection.
 
Thanks, everybody. The client and I have agreed to allow the contractor to use galvanized in the installation under consideration (i.e., that the answer to my question was "#1"). The fact that your opinions matched our interpretation helped us come to that decision.
 
I would agree that it's #1. The problem with it is, is that when you use you channel locks to tighten it, you damage the galvinization and it should be wrapped like they do with gas line, but nobody does it.
 
paul said:
Didn't the 2008 address this and remove the "or" and replace it with "and"?
Click to expand...
No, it's still an "or." What they did change was to introduce something called "red brass RMC." I still don't know what that is about.
 
From the UL Guide for rigid conduit (DYIX).
Galvanized rigid steel conduit installed in concrete does not require supplementary corrosion protection.
Galvanized rigid steel conduit installed in contact with soil does not generally require supplementary corrosion protection.
In the absence of specific local experience, soils producing severe corrosive effects are generally characterized by low resistivity (less than 2000 ohm-centimeters).
Wherever ferrous metal conduit runs directly from concrete encasement to soil burial, severe corrosive effects are likely to occur on the metal in contact with the soil.
Click to expand...
 
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