Old fuse boxes and mineral cables from 60s, is a complete rewiring required?

[wtlh]

Hi,

We have just bought a flat that was built in the 60s. We had three sparks coming to the property and looked at the electrical systems as we wanted to install new storage heaters in the bedrooms. The indication we got is that the main circuit in the flat has not been changed since the 60s, and bits and pieces, such as the electric shower has been added on later. There are very few consumer sockets in the rooms.

The recommendation I got from the sparks has been rather different.

One recommended me to do a proper test first.

The second one said that the 60s wires are made of good quality materials and they should still be okay. But adding additional storage heaters will be difficult. He recommends just ordinary electrical heaters. Only the fuse boards will have to be replaced.

The third one, said mineral cables are used to connect the power from main, which uses the copper casing as earth, and it is not up to the standards of current regulations. He said that it will just be a waste of money to do a full test, because in his view the test will just confirm the fact that wiring needs to be changed anyway, and the flat will fail an electrical inspection just from what he has already seen. So he suggested a complete rewiring.

Ideally, I guess a complete rewiring will solve all the problems associated with the lack of storage heater in the bedrooms and the lack of sockets. However, obviously it will also cost a lot more. I am just worried that if we go for the cheaper option of just adding the E7 line and storage heaters into the bedrooms, then some other problems could prop up when we redo the kitchen and bathrooms for example, or if we try to install newer appliances, and it could end up being more expensive.

Your advices would be much appreciated.

Cheers

 

[trev]

Take electrician #1 He's the only one who has given good advice.
#2 is talking rubbish because 60s wiring could be breaking down. There's only one way to tell
#3 is talking rubbish because mineral insulated cables are not used in a mains supply. At least not one that I've seen in 34 years in the trade. If MI cables are used in an installation, if they are done properly they will outlast just about anyone on this forum

 

[trev]

#3 is also talking rubbish because he's not thinking about the benefits of a test and what that will tell him. He's only seeing the £ signs of a full rewire (which you may well need btw)
Give him a call and ask him how a rewire of your house will deal with these supposed DNO MI cables.
When rewiring, the DNO cables are not touched by us.

Tell you what guys, that's the best one I've heard in years. MICC not compliant with current standards PMSL

 

[telectrix]

you got turbo fingers, trev. ???? totally agree with your post. test first, then remedy as required.

 

[Zebra Stripe]

Agreed, 3rd one is a knob and making it up as he goes along. Go with EICR and get it all on the record as it were

 

[wtlh]

Hi Guys,

Thank you very much for the quick reply. This is the type of advice I need!

I will definitely call up and get the test done first.

Do you know what the test will an will not tell me? Will it tell me which wire goes to where, and what are the maximum load capacities in the wires etc?

Cheers

 

[trev]

It will tell you nothing really, it will tell the electrician all he needs to know about the condition of your installation though. It's then up to him to talk you through it and explain what everything means.

 

[telectrix]

it'll tell you all that and more. the electrician will be able to advise on whether or not you can add extra loads and where.

 

[wtlh]

Thanks! So I should ask for a "EICR" test, correct?

 

[Octopus]

Thanks! So I should ask for a "EICR" test, correct?

Yes - but ask him 2 questions:

1. How long does he anticipate being in the flat

and

2. How much he charges.

A proper EICR should be about 3 hours on site and 1 to 2 hours filling forms etc at home. Anything less is probably not worth doing and if that's the case get another spark to quote for an EICR.

Out of interest where in Berkshire are you? The border isn't far from me!

 

[telectrix]

yep. expect to pay around £200-£250 .

 

[wtlh]

Yes - but ask him 2 questions:

1. How long does he anticipate being in the flat

and

2. How much he charges.

A proper EICR should be about 3 hours on site and 1 to 2 hours filling forms etc at home. Anything less is probably not worth doing and if that's the case get another spark to quote for an EICR.

Out of interest where in Berkshire are you? The border isn't far from me!

I am in Windsor.

 

[pjcomp]

If the flat's been wired in MIC it might be the walls, floors and ceiling are all concrete with the cabling embedded - got several blocks like that round my way. Chasing new cable into solid concrete isn't impossible, but it's not much fun, either, for contractor customer. If you have more socketry/circuitry installed you may be looking at surface-mount in trunking.

pj

 

[shanky887614]

If the flat's been wired in MIC it might be the walls, floors and ceiling are all concrete with the cabling embedded - got several blocks like that round my way. Chasing new cable into solid concrete isn't impossible, but it's not much fun, either, for contractor customer. If you have more socketry/circuitry installed you may be looking at surface-mount in trunking.

pj

I was under the impression you are not always allowed to chase ceilings etc because it can weaken the strength feel free to correct me.

depending on the size of the rooms and if you dont want surface then a possibility is having it boarded straight over the concrete but you will lose a little room space but imho a much better finish if cant chase

 

[wtlh]

I think the floor and the ceiling are concrete. The outer walls and the wall between the living room and bedroom 1 are brick (told by surveyor). The rest of the walls produce hollow sounds when I knock on them, so they are probably plasterboards. The ceiling when you knock on it sounds hollow throughout the flat. I am suspecting it is a false-ceiling board fixed onto the concrete above via wooden beams.

The neighbours did a rewiring about 10 years ago, and everything is hidden, no trunking at all. So fingers crossed that we will not need trunking.

 

[somersetsparks]

Take electrician #1 He's the only one who has given good advice.
#2 is talking rubbish because 60s wiring could be breaking down. There's only one way to tell
#3 is talking rubbish because mineral insulated cables are not used in a mains supply. At least not one that I've seen in 34 years in the trade. If MI cables are used in an installation, if they are done properly they will outlast just about anyone on this forum

Trev, mineral supplies from ryfield units to flats used to be common around here, usually they potted but not glanded at the consumers fuse (red link) end and quite often have just the sleeved tails taken off into the bottom of the service head, very often 6mm or 10mm pyro's. Most were supposed to have been replaced with split-con by now but haven't.

 

[trev]

I've seen them coming from a meter room before, from a switchfuse but that's not the DNO supply so yeah I know what you're saying mate

 

[somersetsparks]

Yeah, a lot of these flats would have originally had meter rooms but most have had meters moved into the flats due to unwanted visitors and vandalism in the meter rooms, on a side note, some street lighting around our area is run in Pyro!

 

[Knobhead]

If anyone knows Victoria Centre in Nottingham (Fairy Towers) all the flats are supplied via MICC’s which are the DNO’s responsibility.
The whole place is causing quite some concern regarding supplies. It’s about on its last legs. It’s a case of when the supply fails, not if.
Harmonics and terrible PF are taking their toll on the transformers and risers particularly the neutrals.

 

[Adam W]

Just to throw my 2ps worth in:
There's nothing 'wrong' with MI cable as such and it's certainly not 'obsolete', although it's used much less frequently nowadays. The main reasons for this is that it's expensive and can be time consuming to install unless the electrician is used to using it. The reason it wouldn't be OK is the mineral powder used for insulation needs to be kept dry. As already mentioned if the ends were made off properly it should still be fine, but the electrician will do an insulation resistance test to measure just how 'fine' it still is.

I would be more concerned about the layout of the wiring - by the sound of it you're going to need more sockets which will involve new wiring, and the layout could well need changing. Also it could be that all the sockets are on the same circuit, likewise all the lighting. Under the current regulations rcd protection is generally required for all circuits in a way as to prevent disruption, which usually involves 2 rcds in the consumer unit with a lighting circuit and power circuit on each, split across the board so for example if one lighting circuit trips you still have the sockets working in that room so can use a table lamp, light from the tv etc.
This alteration of the layout may mean that although the existing cable might be fine, keeping it could just seem like an exercise in conservation and replacing the whole lot might work out easier and cheaper.

I don't see why you couldn't have night storage heaters, but you'd usually need a separate consumer unit and feed from the meter for them. It's worth considering your energy usage - the whole point of storage heaters is they use cheaper off peak electricity, but on an economy 7 tariff you pay a lot more for electricity during the day, so a modern electric radiator might work out cheaper for you.