concrete electrode

[azaher1972]

we may use the buried part of foundation as grounding electrode on certain conditions
in code i read that this part should be in direct contact with the surrounding soil
actually no buried foundation is in direct contact with soil because concrete is always covered either with membrane sheets or Bitumen paint for isolation and safing the concrete
so doest it mean its impossible to make use of this part or what ?

thanks for answering my question in advance

 

[david]

I just went on a google search and look at pictures of concrete foundations in Saudi Arabia and i'm not seeing the footings isolated from contact with the earth

If your footing is isolated from contact with soil I’m not sure how it could be considered a CEE

 

[Dennis Alwon]

Is the concrete covered on the top? If so I believe you are okay, however if the plastic is on the bottom then you cannot use the concrete as an electrode. I would definitely use it if only the top was covered.

Informational Note: Concrete installed with insulation, vapor
barriers, films or similar items separating the concrete from the
earth is not considered to be in “direct contact” with the earth.

 

[kwired]

The whole key to this being an effective electrode is the amount of contact with the earth. If you have conditions mentioned in the informational note Dennis posted, you have reduced that contact. You may still have semi effective electrode but it will at very least have some capacitive impedance in it.