Undersized Water bonding advice please.

[PJH2903]

Been out to price for another CU change this evening and would appreciate the groups advice.
When looking at the job I noticed that the water bonding is undersized at 4mm on 25mm tails so should be 10mm which is not a problem as I can include that in the quote.
Gas bonding has been done and is 10mm.

The problem I have is when I have gone to look at the main stopcock in the kitchen all the pipework has literally been plastered into the wall so all you can see is the handle of the stopcock. Told the client that I would need to chase the pipework out so I could check and upgrade the bonding accordingly but they would not be keen in this as the kitchen was only redone earlier in the year. The nearest place I could put my bonding without chasing out would be at the kitchen sink which is about 2m away from the stopcock.

How would you all approach this?
Thanks

 

[telectrix]

what'st he earthing arrangement.TN-S or TNC-S?

 

[Deleted member 9648]

If you can verify the incomer up to the S/C is plastic then you can probably forget it, otherwise it will need to be upgraded. No getout on that one.

 

[Strima]

Put it where you can then and make a note on the certificate stating client wouldn’t give permission to chase the wall out.

You can only do so much.

 

[Deleted member 9648]

what'st he earthing arrangement.TN-S or TNC-S?

Not really relevant, at 4.0mm it's undersized

 

[PJH2903]

what'st he earthing arrangement.TN-S or TNC-S?

TN-S

 

[PJH2903]

If you can verify the incomer up to the S/C is plastic then you can probably forget it, otherwise it will need to be upgraded. No getout on that one.

Can't see the pipework but the house was built in the late 60's so I would imagine it's going to be metal.

 

[Sintra]

Give it a quick check to see if it is actually extraneous.

 

[Deleted member 9648]

Well for TNS the minimum is 6.0mm, not 10mm. If you state on the EIC that there are no signs of thermal damage and you consider it adequate then crack on. Your call, your name on the cert, but realistically it's never going to be a problem despite what I posted above.

 

[PJH2903]

Put it where you can then and make a note on the certificate stating client wouldn’t give permission to chase the wall out.

You can only do so much.

Think I'll quote for both options and then ring Stroma Tech support in the morning to see what their take would be.

 

[littlespark]

"Reasonably practicable"
In relation to how close to the stopcock you need to be. Its not practicable to chase out the pipe, so you put as close as possible - under the sink. At least it can be seen for future EICR's

 

[Wilko]

Can't see the pipework but the house was built in the late 60's so I would imagine it's going to be metal.

Never say never
My home's about that age but at some point they've replaced the water service and there's a nice blue plastic pipe coming up to the stop cock.

 

[Ian1981]

You sure it’s 4mm and not 6mm?

 

[PJH2903]

You sure it’s 4mm and not 6mm?

Yes, pulled a bit of 6mm of the van to compare it with to check the size as it looked so small next to the 10mm gas bond.

 

[Octopus]

There are times when common sense has to be the only course of action ...

Run the 10mm to under the sink .......then it won’t get filled over ... and will be accessible in the future

 

[magnoliafan89]

Give it a quick check to see if it is actually extraneous.

How is this done?

 

[PEG]

Spooly stretchy poky testy

 

[Deleted member 9648]

The results of 'is it extraneous?' tests are often misleading because of parallel paths, particularly if there is a combi boiler where the water service may be mechanically connected to the gas service.

 

[Midwest]

Well for TNS the minimum is 6.0mm, not 10mm. If you state on the EIC that there are no signs of thermal damage and you consider it adequate then crack on. Your call, your name on the cert, but realistically it's never going to be a problem despite what I posted above.

I don't have the periodical, but I recall the Connections rag, changed its guidance on 'no thermal damage' scenario, to if it doesn't comply, then 132.16 must be observed, regardless of no damage.

The idea being, it might not have had the situation arise before, but it doesn't mean it might not happen in the future.