Can EMT be direct-buried?

The 2005 National Electrical Code (NEC) allows the direct burial of all three products as noted in their respective Articles:

RSC Section 344.10 (B) Corrosion Environments. “RMC, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and judged suitable for the condition.”

IMC Section 342.10 (B) Corrosion Environments. “IMC, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and judged suitable for the condition.”

EMT Section 358.10 (B) Corrosion Protection. “Ferrous or nonferrous EMT, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and judged suitable for the condition.”

 EMT are all “protected by corrosion protection” due to the zinc coating that is applied during the manufacturing process. However, in severe corrosive environments, the designer or AHJ may decide to require additional or supplementary protection.

EMT in direct contact with the soil generally requires supplementary corrosion protection. However, local experience in some areas of the country has shown this to be unnecessary.

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