Eart bonding pipes - lead to plastic to copper

[Spark123]

Guys I'm sorry but no-one has really answered my question.

I repeat -
"I understand the lack of requirement in the regs for supplementary bonding in kitchens but question that there is no bonding at all on the water system.
As the incoming goes from lead to plastic to copper within a couple of metres of entry do I add supplementary bonding after the plastic to be on the safe side?"

Where the transition from plastic is to copper, you need a main equipotential bond connected between copper pipework and the MET (main earth terminal), size of cable depending on the type of supply TT, TN-S, TN-CS. It is arguable to also bond the lead pipe, although you really should be thinking of having this replaced with plastic, sooner rather than later as it is almost inevitably causing poisoning.
You may also consider getting an electrician in to do a PIR (periodic inspection report) as there may be more issues with other main equipotential bonds and supplementary bonding.

 

[ban-all-sheds]

If the entire water system in the house is isolated from the incoming supply by 2m of plastic pipe, i.e. 230kohms for 15mm or 130kohms for 20mm pipe, then I'd not bond after the plastic.

Is there a low-resistance path to earth via the CH boiler and the gas pipe?

 

[ban-all-sheds]

Where the transition from plastic is to copper, you need a main equipotential bond connected between copper pipework and the MET

Why?

What's it for?

 

[Spark123]

Under the same argument, if a water supply enters a house in blue plastic pipe and then terminates into copper pipe, why do we need a main eq bond there?

 

[ban-all-sheds]

I agree - why do we?