UK Lead sheathed cable problems!

[acuk2101]

Hi guys sorry in advance for the long read,

I have just started a renovation project in Hampstead on a second floor flat. Luckily the flat is a bare shell at the moment so I have been employed to rewire the flat entirely. The flat was constructed in the early 1900's so I was sure to encounter some problems! The flat has been updated at some point (in terms of newer wiring) at some point in the 80's, the original CCU position has changed but is now having a complete overhaul.

So, here is my problem that I am hoping to get some advice:

The original wiring is still in the walls and under the floor, this has been disconnected (some time ago) and is old lead sheathed cable. The problem is that the all of the sheaths are at 120VAC, the internal cores tested between 6 and 24VAC, on further investigation the interferace is from the flat underneath. I uncovered some 'twist and taped' joints where I found the voltage to be 247V, which is fed from downstairs. I managed to speak with the owner and he begrudgingly turned the main switch off saying 'It won't be my board, mine is quite new', revealing a 20 year old Voltex board, no RCD, this fixed the problem. The insulation is badly damaged and obviously the cable shouldnt be in service. Some of the live lead cables from downstairs run on the top of my joists, so need to be removed as they shouldnt be there and wont meet building regs. I am unsure if the cables should even be live as he has had a newish kitchen and bathroom, so these issues should have been addressed when these were installed (Its obviously not connected to earth so how did they get a Zs??)

So should I leave the cables on my side of the joist as they are? (very aware that I dont want to become responsable for the downstairs flat, but conscious that the outer sheath is live)

Should I turn the power off downstairs, remove my cables and then leave the rest as it is?

The installation below needs attention, I will speak to the owner, but ultimately is this for the leaseholders to decide on the course of action due to the hazards?

I am a bit lost with this one to know what the next course of action should be, any help would be appreciated!!

 

[buzzlightyear]

if you are rewiring the flat and you have found some cables that entre you flat and leave them alone ,but if you have found them in a bad way ,speak to the owner of the flat .dont turn off the flat below it is not your problum. if you think it is a fire risk then tell them .

 

[westward10]

Sounds like and obviously was a single dwelling. I would speak to building control and tread with extreme caution. If you are a scheme member it may be worth a call with them.

 

[MJPD29]

Very tough one if the neighbour does not cooperate. It's a bit off subject, but do you have any pics of the lead cable. I'm always interested to see it still in service

 

[littlespark]

Tell the downstairs neighbour that his electricity is “leaking” and will be paying for it through his meter.
Can you see which circuit these lead cables come off?

 

[Baddegg]

Interesting thread, I think you are going to have no end of problems here if the as others have said the neighbour remains uncooperative, I’d involve building control, the lease holder and the person that employing you before I went much further I think, we have an abundance of old Victorian houses down here split in to 2 and more flats, seen loads of the circuits tapped into and crossed sometimes it’s hard to know whats what!....keep us posted and good luck ?

 

[acuk2101]

Thanks for the replies! Yes, nightmare job problem is that I can’t see the complete run of cables just yet. Once the rubbish has been cleared I’ll be able to lift more boards. I would assume that when they have been adding bits downstairs they have tapped into the lighting circuit, but as said above it could have been chopped into anywhere! I’ll let the client know what the situation is and then he can liaise with the neighbour. I’ll let you know the outcome
[automerge]1575447016[/automerge]

Tell the downstairs neighbour that his electricity is “leaking” and will be paying for it through his meter.
Can you see which circuit these lead cables come off?

Think it’s the lighting, but not taking any chances!
[automerge]1575447127[/automerge]

Very tough one if the neighbour does not cooperate. It's a bit off subject, but do you have any pics of the lead cable. I'm always interested to see it still in service

Not in service my side, but this is what I have:

Plus an old three phase service head outside which has a bird nest in.
[automerge]1575447173[/automerge]

Sounds like and obviously was a single dwelling. I would speak to building control and tread with extreme caution. If you are a scheme member it may be worth a call with them.

I’ll give them a call today to see what they recommend!

 

[davesparks]

As its a second floor flat it is unlikely that it's anything other than lighting for the first floor flat in the floor void.
The power for the first floor flat is likely to be in the ground floor flat's ceiling void.

The lead cables have obviously been butchered at some point as the sheaths form the cpc and would have been connected to earth when it was installed.

 

[PEG]

Hi,i would firstly,inform the owner,and consider including any other affected flat owner,in that discussion.

Secondly,especially if further boards are lifted,assess the actual risks. This would be whether the voltage readings are 'real' ,if anything can be referenced back to it's own source earth,etc.

Thirdly,ensure where the properties actual boundaries are,and if there exists any paperwork,leases,covenants,etc,to designate current and future responsibility.

A fourth point,would be that it is not uncommon,to reach an agreement,with any adjacent property owner,usually in association with their agent or spark,to fix cabling and/or conduit,in anticipation of their future refurb needs.

This can be drawn,photographed and accessed from points in their ceiling,to allow future improvements,without the "fun",of a ceiling strip?

Sometimes,if what you find is not WW3....you just have to board up,and forget it.

This is why i would not own a flat,without owning all of them...?

 

[R-fur]

Have you checked with a low impedance tester that it is not a phantom voltage being transferred by sheaths that are bonded together but not earthed?

 

[Midwest]

Good advice, time to pause and take stock before venturing any further.

 

[UKMeterman]

One route could be to call the DNO and report the unsafe install, they may decide to pull the fuses on it...