Roof Earthing

[Is it live?]

Guys, I generally have had a pretty narrow industrial focus and have recently branched out into domestic and commercial and have come across a situation that just doesn't feel right. I have been asked to do an EICR at a commercial property (listed building) where a known defect is that one of the lighting circuits has no CPC and I have had a quick look and agreed that this can be resolved. However whilst I was running around looking at this problem I noticed that the building has a metal internal roof. It kind of looks like the inside of a nissan hut, with sheets of curved galvanised corrugated metal bolted together and (I assume to something above). However, there is no continuity between the roof and the main earth. Is this permissible in the view of you guys?

 

[telectrix]

IR test from steel roof to MET. if it reads > 22 K ohms, then it's not extraneous and does not require bonding.

 

[SirKit Breaker]

If there is any electrical equipment mounted to it or cables passing through it, it may need bonding! Otherwise as Tel.

 

[Engineer54]

IR test from steel roof to MET. if it reads > 22 K ohms, then it's not extraneous and does not require bonding.

But it may need ''Earthing''!! lol!!

 

[mechelec]

Will it introduce an earth potential ? I doubt it unless like a Nissan hut it extends down to the floor.

 

[telectrix]

but nissans are insulated from earth by the tyres.:24:

 

[SirKit Breaker]

but nissans are insulated from earth by the tyres.:24:

Not round my way mate, they are insulated form earth on bricks!