bonding of aluminum structures

[james moore]

are aluminum structures (screen enclosures,lani,room,etc.) required to be bonded when water (pool,spa,etc.) is not present.I have a building dept. that is quoting 250.116 fine point notes and is requiring all aluminum structurs to be bonded. I am looking for some clarifaction for myself and/or the building dept. thanks in advance

 

[bphgravity]

Unless amended by their local code, the building department cannot enforce a FPN or require aluminum structures to be bonded unless they are likely to be energized by a branch circuit or feeder. The state of Florida has such an amendment that would require the bonding.

 

[hillbilly]

90.5(C) Explanatory Material.
"Fine print notes (FPN) are informational only and are not enforceable as requirements of this code".

Are the aluminum structures "likely to become energized"?
steve

 

[petersonra]

I think a good argument can be made that the aluminum structure constitutes a required grounding electrode 250.52(A)(2) if bolted to a concrete pad.

A structure that is bolted to a concrete pad is certainly effectively grounded.

(2) Metal Frame of the Building or Structure. The metal
frame of the building or structure, where effectively
grounded.

 

[james moore]

I do not see how it could become energized unless a direct hit from lighting and then I would think being as it was in direct contact with the structure it would be grounded as if the lighting hit the roof or exterior wall. I am also understanding that a grounding rod would not be suffecient. The only proper way to ground is to attach to existing grounding rod which in many cases may be the other side of house.

 

[petersonra]

I do not see how it could become energized unless a direct hit from lighting and then I would think being as it was in direct contact with the structure it would be grounded as if the lighting hit the roof or exterior wall. I am also understanding that a grounding rod would not be suffecient. The only proper way to ground is to attach to existing grounding rod which in many cases may be the other side of house.

Sufficient is not the issue. Anything that gets a direct lightning strike is likely to sustain damage unless a fairly expensive protection system has been installed.

If there is a rod, it might well be in an inconvenient place but if the aluminum structure qualifies as a grounding electrode, IMO, you are required to bond it to the other grounding electrodes. Nothing says it has to go to the rod. it could go to the water pipe, or the ground bar at the service point, or to the CEE. Whatever is most cost effective is where I would land it.