In article ,
Adrian Brentnall adrian-the papers and the writes:
HI all
We're hoping to sell our bungalow soon in anticipation of an overseas
move (Ireland).

With this in mind - I'm looking around the property at things that a
surveyor might find fault with. Have already sorted all the little
'nearly finished' bits of decorating that we've lived with for 5 years
g - and now thinking about the electrics.

Although the electrics are now much improved over the original
slightly dodgy, elcb, wire-fused installation - one thing that I never
got round to was the earth bonding. I've read up in the faq, and in my
Which DIY Electrics book - but I'd like some clarification if
possible..?

1) We use Calor (big red cylinders) for gas. Should the incoming
small-bore gas pipe be bonded back to the main earth ? - even though
the gas hob and the gas cooker are both connected to mains earth via
their own 3-core cables....

Yes.

2) The airing cupboard looks like a good place to connect 'everything
to everything' - as the central heating piping, the power-shower
pipework, the solar heating pipework, the general hot & cold pipework
and the water pipe from the well all pass through here. Is bonding
here a good idea / acceptable ?

Not necessarily. Bonding of sevices which come in from outside
needs to be done where they enter the house, normally within
300mm on house side if the isolating valve. Bonding of bathroom
pipework should be done in the bathroom or immediately adjacent
to it. If the airing cupboard fits one or both of these
requirements, then that's a good option. Otherwise it's a waste
of time as you will still need to bond at the required locations.

3) I understand that bonding hot, cold and exposed metalwork is
necessary at kitchen sinks and bathrooms - does this bonding need to
extend back to the common mains earth by the switchboard ?

Only necessary in bathrooms. People often do kitchens too, but
there's no requirement to do so in the regs. The bonding should
be to the earths of local circuits -- a dedicated earth conductor
back to the switchboard is not required for bathroom bonding (it
is for the service bonding above). Normally, 4mm² earth cable
is used for bonding, but that can be dropped down to 2.5mm² if
the cable is protected from damage.

4) Anything else I should be thinking of ?? regarding a possible
survey...

Water supply should be bonded back to the main earth terminal
too. Service bonding should be done with 10mm² earth wire.
The main earth terminal should be connected to the supplier's
earth connection with 16mm² earth wire.

--
Andrew Gabriel