No bonding on new build

[davey81]

Hello all,

I was at a new build house today (build in 2008 so not brand new), there was no main bonding to the water pipes however the main service pipe was plastic (the rest of the installation is copper). Is this correct? and would you say it was best practice?

What I gather is a water pipe supplied by a plastic pipe cant introduce a potential and therfore isnt an extraneous conductive part, therfore doesnt need bonding. However I've seen a live cable make contact with plumbing and imagine it would be best to have copper pipes bonded. Any opinions on this?

 

[Andy™]

its not extraneous so doesnt need it - although it will most likely be earthed indirectly via boiler anyway

 

[batty]

Definitely should be bonded only time pipes don't need bonding if they are all plastic throughout.

Welcome to the forum

 

[Andy™]

Definitely should be bonded only time pipes don't need bonding if they are all plastic throughout.Welcome to the forum

no definately... pipes only require bonding if they are extraneous... if its a plastic feed, then its most likely not. not really relevent to upstairs flat, but pipework if is contact with ground (i.e underfloor) then it could become extraneous because of that

 

[batty]

[quote name='Andy

 

[steptoe]

deffo needs bonding, water pipes have been a variation of plastic/copper for a long time now,

the bit before the stop tap is of NO concern to you, the bit after is the bit you bond.

I'll bond 6" of copper if it covers my ass.

 

[davey81]

That was quick, thanks.

I think this is a bit of a grey area hence the two opposite answers given. If it was me I would have bonded. Andy, its not earthed indirectly (>20 Mohms between MET and pipework).

 

[tom1]

osg says it may not need bonding

 

[Andy™]

Plastic mains have been used for the past 40 years metal pipes require a main bond simple.

its not extraneous so hasnt got to be bonded. but its usually easier to bond it (i always bond it unless its plastic both sides at stop tap)

 

[steptoe]

what about the prat changing the lamp in the bathroom balancing between the bath and the radiator.!?

 

[Lurch]

I'm not usually a fan of just bonding anything in sight regardless, but I, and I don;t know many others that don't, always bond the mains water incomer where the internal is copper and the external is plastic. Covered for any future eventualities.

 

[Andy™]

what about the prat changing the lamp in the bathroom balancing between the bath and the radiator.!?

if the pipe was not extraneous, i.e cannot introduce a potential, then it follows that it cant export a potential.... i.e your prat changing the lamp.

however, it will be earthed at some point indirectly anyway. i.e boiler will have an earth to metalwork, which then earths pipes

 

[PC Electrics]

If you're getting 20Mohm between the pipework and MET, then strictly speaking you do not need to bond.

However I agree with Lurch. It only takes someone to modify the pipework at some time in the future for it to suddenly introduce earth potential and need bonding.

In your situation, when you issue your MWC (or on your invoice if the work doesn't require any certs) put a note that if the pipework should be modified in the future, then it should be retested to see if it needs bonding. If you've got a labeller, you could put a note on the CU.

 

[kme]

I`ll agree with PC on this; although, I`d generally bond it anyway, so it`s "future-proof".

As the (very) earlier thread, with Specloc`s experiment, there is the (possible) conductivity of the pipe`s content to contend with.........

KME

 

[steptoe]

I dont think water in this context is deemed to be conductive,

but I would deffo want a very valid reason as to why the main incomer had not been bonded especially as the rest of the dwelling was in copper.

I really wouldnt want to try and argue this to anyone TBH, so I do it, ALWAYS, without fail

 

[davey81]

Thanks for all your responses, you have all been very helpful

I

 

[sparkycomuk]

Looking at the original post... It seems like a standard Installation...Plastic supply/copper in the house.....I'm sure even if you take into consideration ..the >1667ohm jargon....the incoming supply's..eg....gas/water /oil/etc...If they are conductive still have to be earthed at incoming source......Sorry can't quote exact regs

 

[mikep]

For the sake of some cable, bonds and peace of mind I like a bit of bondage, just in case a potential is introduced.

 

[davey81]

Just to give everyone an update:

It appears the new house builder does not bond to water due to the plastic main in. Rather then try and argue the cause with them (they didnt appear to back down) I installed one myself.

 

[SPECIAL LOCATION]

Just to give everyone an update:It appears the new house builder does not bond to water due to the plastic main in. Rather then try and argue the cause with them (they didnt appear to back down) I installed one myself.

4.4 Main protective bonding of plastic services

Page 29 on site guide.

and

4.7 Supplementary bonding of plastic pipe installations

Page 31 on site guide.

come to mind???

I suspect the house builder was probably right?

What was the resistance between any metal pipework & earth prior to you putting a bond on?

:|