Extraneous Conductive Parts

[walsall]

In a house conversion there is a huge steel goalpost beam(2,000 kgs worth) than spans 3 rooms, and supports the floor in 4 others. Theidea is that it will be completely covered at the end of it all but there is cable tray clipped to it and cables running along it. (The web provides the only cable routes in the property - argggh)


I've made the call to bond it as it is substantial and it’s bolted to the foundations, below the DPC etc. At present if you get a high resistance to Earth >500kOhm. Strictly, I don’t think it needs bonding, but it seems the sensible approach.

The builder thinks I’m mad – (and I probably am).

What would you do in this situation?

 

[telectrix]

411.3.1.2 (v). the key word is exposed.

 

[walsall]

411.3.1.2 (v). the key word is exposed.

Indeed, and I'm guessing that it still will be exposed somewhere after I've tested and switched on.




Indeed, and I'm guessing that it still will be exposed somewhere after tested and switched on.

 

[wozz]

will it not be fire boarded then?

 

[walsall]

will it not be fire boarded then?

when the builders finish it will....

 

[tony mc]

I thought the days of bonding everything had passed.

If it is as you say >500 k Ohms why are you going to bond it and introduce a earth potential ?

Its way above 22k !!!

 

[Knobhead]

Is it a major problem to get a 10mm to the beam? If other cables are running along it I would think not. Just bond the damned thing for you own peace of mind.

I’m surprised you’re getting such a high reading if the foundation blocks are properly constructed using re-bar. By rights they should form an Ufer earth. (Look it up)