Running main bonding conductor

Now that's one I have never heard asked before. Nice one:-)

I have always installed it in the safe zones or followed a, c or d here

I guess it needs protection in the same way but for different reasons. You could drill through the main bonding conductor and never know about it. Simon.

Its rare to see one* that is not surface wired (or for that matter loose) IME

(*if you see what I mean!)

I've always surface mounted it, along with the supply tails. I like having supply tails visible for ease of visible inspection, and to get that small addition 5%(?) of current-carrying capacity. Useful when most of my installations have to be designed from scratch rather than book-standard circuits.

JGH

That's fine where everything is nice and close together. If your water stop tap is in the kitchen, with gas an electricity in the garage, for instance, there may well be a considerable run of cable.

Chris

I am sure my customers would be delighted to see me clip a 10mm green/yellow down the wall when doing a rewire:-)

My FiL's house has the earth wire coming out of a hole in the front wall, wandering (unprotected) across a couple of slabs an (presumably) to an earth-rod in the front garden. And it's a recent rewire, too.

Who says you need to use green/yellow cable? And might that also just possibly be the answer to the original question?

Reg. 522.6.6 (about the zones) only applies to "A cable concealed in a wall ...."

IIRC ('cos I'm too mean an amateur to have bought the regs.) the regulations for the main equipotential bonding (544.1) specify a conductor but don't require it to be a "cable". As I can't find a definition of cable I assume it takes its ordinary meaning, so if you use something that's clearly not cable as the conductor - eg copper pipe or lightning conductor strip? - for the main equipotential bonding then ..........?

Of course it might be a bit of a challenge to fit copper pipe into the MET and clamp it to the water pipe though I'm sure I'd find someone here to tell me what to do :))

That said, I suspect I'd fail the unwritten "no bloody smart-arse shed-lawyer solutions" regulation ;)