Bonding Rebars in Building Addition

[dmanda24]

Hello all, I have a commercial building addition where the original building already has a concrete encased electrode, the engineer wanted another concrete encased electrode on the addition, I showed him 250.52 (A)(3) and he gave up on that, but now he wants me to tie the rebars together from the existing building and the addition. I don't think he is right but I cannot find a code reference other than 250.52 that says otherwise. Your Help is much appreciated.

 

[kwired]

Hello all, I have a commercial building addition where the original building already has a concrete encased electrode, the engineer wanted another concrete encased electrode on the addition, I showed him 250.52 (A)(3) and he gave up on that, but now he wants me to tie the rebars together from the existing building and the addition. I don't think he is right but I cannot find a code reference other than 250.52 that says otherwise. Your Help is much appreciated.

NEC does not require it. He may have reasons to do so, it is his design.

 

[dmanda24]

NEC does not require it. He may have reasons to do so, it is his design.

His reason is that he thinks it is required, we are both trying to minimize cost to owner on an already over budget project, if I show him is not required he will not require it.

 

[kwired]

His reason is that he thinks it is required, we are both trying to minimize cost to owner on an already over budget project, if I show him is not required he will not require it.

Last sentence of 250.52(A)(3)

 

[infinity]

As Kwired stated it's not required. Although it was never required the section he quoted was added several code cycles ago to avoid any confusion.

 

[dmanda24]

Found a text on the 2017 NEC handbook describing this situation I think this will suffice.
"Some buildings or structures may have discontinuous segments of a footing or foundation
that individually qualify as grounding electrodes per this section and
once one has been bonded to the grounding electrode system, the
remaining ones are exempt from any bonding or grounding requirements."
Thanks you all.