Trick equipotential bonding

Not sure that all the builders actually pass the C and G to be honest. Forget basic electrics, what about water... I've just had a chap build me a workshop where the felt roof tucked neatly behind the Fascia instead of curling over in front of it into the gutter, so the water would be ducted indoors, and the gutter stays more or less empty. And flat roofs are not supposed to be truly flat !!. If I'd really wanted to come home and spend a weekend cursing and redoing it I'd not have employed someone who claimed some expertise in the first place. So maybe you expect  bit much from the average driveway paver as there are truly some total muppets out there.

Anyway, to your point, are you saying there is a bond wire already but the route is unknown, or that it is not connected anywhere ? A long wander lead  test will probably tell you. Given that the resistance of metal pipe is lower per metre than the cable we bond with (22mm dia copper tube is about 60mm2 equivalent copper area) the idea that the bond not being within 60cm is actually a problem is not really true, more of an ease of  inspection issue than an electrical one unless the pipe has an insulating  break in it.

Is this a TT house then or a TNx with augmenting electrode ?

If the former it sounds EVSE ideal if the latter may be an O-PEN box rather than too much digging or drilling.

M.

I’m not entirely sure it would have the desired effect as it is.

A 22m pipe (or even a 15mm one) has a a much bigger copper c.s.a. than a 10mm² bonding conductor - so the position of the bond in terms of electrical effectiveness isn't really an issue (in theory the lowest impedance to the point of entry would be achieved by bonding wherever the gas pipe was closest to the MET). The reason for bonding as close as practical to the point of entry is to avoid losing the effectiveness of the bond if insulating sections of pipework/fittings are introduced at a later date (if you bond the pipe of pipe that's actually introducing the potential, it doesn't really matter about all the other bits that aren't).

   - Andy.

It’s a true TT. Possibly, it’s all under the paving. 

Indeed but would it effectively raise the potential of the internal copper work under fault conditions?

Points for accuracy:

Where the meter is external, the bonding conductor should be connected at the point of entry where practicable (practicable means "able to be done") but that is only so that it does not become separated from the actual extraneous-conductive-part by internal pipe alterations otherwise it doesn't really matter. The pipe will have much lower resistance than the bonding conductor.

The "within 600mm." (on the consumer side of the meter) only applies to internal meters even though is not the best place electrically; it should be at the point of entry but the gas companies do not want it on their pipe.

Hmm loop tests will show it I suppose. Less than a few ohms it is not simply TT. more than 100 and it was supposed to be TT but perhaps the driveway chaps chopped the cable.

I guess it all depends on your appetite for hassle.

I'm not going to mention RCD types ;-)

Mike.

I’m feeling pretty comfortable with RCD types these days, even my own house has type A RCBOs. When I have an EV charger I’ll choose one with RDCDD to avoid silliness. I’ve even got one of the surge thingamagigs and just looking forward to being able to afford AFDDs without remortgaging the house!

but the gas companies do not want it on their pipe.

Or more to the point they don't want it on their side of a deliberate insulating joint at the meter position which they sometimes install where they think that diverted N currents flowing through their pipework might be a problem.

   - Andy.

Yet it is that very pipe which will be the extraneous-conductive-part, and

not the consumer's side pipework because of the insulating joint. 

Generally if there’s an insulating joint in the gas pipe the internal pipework does not have a connection to extraneous pipework, so the main protective bonding conductor is no longer required.

However in this instance the consumers pipework runs under the drive, so is extraneous but must surely be wrapped in something to avoid corrosion? It doesn’t sound very clever.