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.

 

[wtlh]

Hi all,

We are booking a EICR, but all the sparks we have spoken to won't be free until in two weeks time... I guess we will just have to wait.

I went onto the Dimplex website, and did a calculation, we will need a 2.55kW and a 1.7kW storage heaters in each of the rooms. Replacing the original hallway storage heaters with the 1.7kW ones, we are looking at a total peak consumption of 7650kW. Given 230V, that equites to total current of 33.26A.

Would a 30A fused cable support such a current?

Another option for us, I guess, if the old cables are sound (they are pvc insulated and does look in good conditions, no split, discolouration or burning marks), is then, to reconnect one of the hallway heater to the living room heater, which runs from its own 30A fused cable directly connected to the meter via its own fuse box. This would even out the distribution of usage on the two E7 lines coming out from the meter.

Does this idea sound reasonable?

 

[2na]

#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

If it is a flat they may well have used mineral insulated cables to supply it. It will be a sub main from the main intake on the bottom floor. Seen it hundreds of times in hove, it never has to be replaced because if untouched it will last forever.

Its a complete lie thats its non compliant, if it tests out fine, it is fine.

 

[trev]

If it is a flat they may well have used mineral insulated cables to supply it. It will be a sub main from the main intake on the bottom floor. Seen it hundreds of times in hove, it never has to be replaced because if untouched it will last forever.

Its a complete lie thats its non compliant, if it tests out fine, it is fine.

Key words there but it's always been from a switchfuse, so not the responsibility of the DNO. That was the point I was trying (badly) to make mate

 

[2na]

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

I knew you did Trev, if you like mineral cable, I like you.

 

[trev]

I love MICC mate.

 

[2na]

So do I. I have recently installed a new zone for a fire alarm in one of my schools, and because it was only 6 detectors/call points, I did it in mineral with my apprentice so he could learn how to do it properly. I even showed him how to strip it with side cutters and by the end of the job, he was very good at it.

It seems to be an art form that is being lost by the current learners, and that to me is a real shame.

 

[trev]

I did a load of fire alarm work a few weeks back, first pyro ends I've made off in years. Took my time with the first couple then I realised I was back on the horse.
We did a very big granny farm so there was loads to do.

 

[2na]

It always takes the first pot to refresh your mind, and then its second nature. I would like to know why they haven't made pozi drive brass screws for outside when its being clipped though. They are the thing that takes the longest......

And please dont tell me they have, I stabbed my finger twice slipping off the screw head.....

 

[trev]

I've seen em mate but it's a bit irrelevant really anyway isn't it. The screws are fastened into a plastic plug!
Oh, forgot to mention. Because I knew this job was coming up I got a shiny new joistripper, £8 inc postage off fleabay

 

[telectrix]

we are looking at a total peak consumption of 7650KW

bloody hell. you running a foundry?

 

[wtlh]

we are looking at a total peak consumption of 7650KW

bloody hell. you running a foundry?

Sorry, a typo, 7650W. LoL

Anyway, here is an update:

I called the electrician (who suggested the rewire) asking him if he is still interested in doing a ECIR first (as other ones could not do it until one or two weeks time), but he just squarely refused, and said it is in his professional opinion that the flat needs a rewire, and he will not do any work on it and then certify it unless it is rewired, so on that note he cannot see a EICR worthwhile... So I thought, oh well, then so be it.

I had a few other quotes too, and incidentally, another apparently quite reputable local firm (they are also Trustmark registered and with quite a few good online references) came (with two electrician) and looked at the flat, and again said that since the wire has not been changed since the 60s that it will have to be rewired. This time they opened up a few lighting switches and noted there are no earth, and said that would mean a "failure" in the report, and I will be only allowed class 2 double insulated switches and lights.

They initially quoted a "couple hundred" for the EICR, because they need to come during the early hours to test the E7 circuit, unless I can convince the power company to switch on the E7 power supply for them in normal hours on the testing day.

They also quoted well over 4 grand for the rewire job, because they will need to put steel tubings into the ceiling cavity, and it will take over a week for the two of them to finish the job, the whole or at least part of the ceiling will probably have to come down, and the quote does not including making good and replastering mg_smile:. After I told them this is way way over my budget and I just wanted a EICR done first, they tried to convince me the EICR will be a waste of money, said they can get the rewiring done for over 3 grand (not including replastering), to come closer to my budget. After they were told that I have contracted another electrician to do the EICR for much less than what they were suggesting, they said that they won't have time to do the rewiring job after the EICR, as they only just happens to have two weeks time window now. I did not buy it. They then later gave me a call offering to do the EICR for the same price as the other electrician and will be able to do it tomorrow. Since I am pretty sure by now that they were just trying to convince me to pay for the full rewire, I cannot trust them to be that objective on the test report. Although time is good, as all other electricians won't have time until a couple of weeks after, I just cannot trust them enough.

So in the end, I ended up asking another electrician, whom I feel I can trust a lot better given the conversations I had with him during his initial visit to do the EICR, but I will have to wait two weeks. If it turns out that I do need a rewire, then I sincerely hope he will have the time to do it immediately, as we will have to move in quite soon.

 

[Octopus]

I still think an EICR is the way to go -as for an "unsatisfactory" because you don't have an earth on the lighting - could it be that the conduit is the earth?

Fingers crossed you'll update us as and when the report is done.

 

[wtlh]

I still think an EICR is the way to go -as for an "unsatisfactory" because you don't have an earth on the lighting - could it be that the conduit is the earth?

Fingers crossed you'll update us as and when the report is done.

I will certainly do. Fingers crossed.

If it is just the lighting circuit that does not have earth, then I guess we can live with that, as long as we only install class 2 lights and do not install new ceiling lights.

Strangely, when they opened up the switch board for the lights, I do see a thin white wire inside together with the black and red wires. I do not know what that white wire is, but they told me it isn't earth, and the circuit definitely isn't earthed. The consumer sockets does have bare earth wires in them, I was told.

 

[Octopus]

I will certainly do. Fingers crossed.

If it is just the lighting circuit that does not have earth, then I guess we can live with that, as long as we only install class 2 lights and do not install new ceiling lights.

Strangely, when they opened up the switch board for the lights, I do see a thin white wire inside together with the black and red wires. I do not know what that white wire is, but they told me it isn't earth, and the circuit definitely isn't earthed. The consumer sockets does have bare earth wires in them, I was told.

Did they get their testers out?

 

[trev]

Just get Murdoch to come and carry out the EICR, you can be sure he'll be thorough and objective and if he says you need to rewire I and many others on here would believe that.
You can then get rewiring quotes in the full knowledge that one is necessary.

 

[wtlh]

Did they get their testers out?

No, they just had a look.

 

[trev]

No, they just had a look.

Quality tradesmen then, If there's a conduit system in place it is perfectly feasible that it is being used as a cpc.

 

[wtlh]

Just get Murdoch to come and carry out the EICR, you can be sure he'll be thorough and objective and if he says you need to rewire I and many others on here would believe that.
You can then get rewiring quotes in the full knowledge that one is necessary.

I have already asked an electrician to come.

He spent a couple of hours with me in the flat on Saturday, opened up the sockets and consumer units etc, and explained to me on a lot of things, and why just by inspection he thinks it is good idea to get the EICR done, as all insulators are PVC and appear in good condition, and by the looks of things whatever work has been done previously was done in a proper way, and people who did the job definitely knew what they were doing.

He said that the mineral cable is one of the most expensive cable types one can get, and if installed properly it will outlast almost anything else, and that the only reason these are rarely used now is because they are expensive, and it is difficult to install, in agreement with the opinion on this forum.

He also said there is nothing wrong with the 60s wires in terms of product quality. And since this flat has been continuously occupied all this time, and previous people were happy to live in the flat without needing much modifications or repair work done to the circuits, there is a good chance that the wiring is still in good condition and it will continue to work, as long as any modifications to the circuits are done in a proper way. So only a detailed EICR can tell if there are any major work has to be done on the existing circuit.

Given those conversations, I felt that this guy is quite down to earth, and he also said that he had been in the trade for over 40 years. I guess it also helped that he once wired a flat in the same development complex. The only draw back is that he is kind of busy.

 

[Octopus]

I have already asked an electrician to come.

He spent a couple of hours with me in the flat on Saturday, opened up the sockets and consumer units etc, and explained to me on a lot of things, and why just by inspection he thinks it is good idea to get the EICR done, as all insulators are PVC and appear in good condition, and by the looks of things whatever work has been done previously was done in a proper way, and people who did the job definitely knew what they were doing.

He said that the mineral cable is one of the most expensive cable types one can get, and if installed properly it will outlast almost anything else, and that the only reason these are rarely used now is because they are expensive, and it is difficult to install, in agreement with the opinion on this forum.

He also said there is nothing wrong with the 60s wires in terms of product quality. And since this flat has been continuously occupied all this time, and previous people were happy to live in the flat without needing much modifications or repair work done to the circuits, there is a good chance that the wiring is still in good condition and it will continue to work, as long as any modifications to the circuits are done in a proper way. So only a detailed EICR can tell if there are any major work has to be done on the existing circuit.

Given those conversations, I felt that this guy is quite down to earth, and he also said that he had been in the trade for over 40 years. I guess it also helped that he once wired a flat in the same development complex. The only draw back is that he is kind of busy.

Which is generally a good thing. Sounds like you have found a good honest sparky too. I bet you're glad you came here for advice now!

 

[shanky887614]

Which is generally a good thing. Sounds like you have found a good honest sparky too. I bet you're glad you came here for advice now!

it is a good think you stuck to your guns and got a proper electrician to have a look.

if a proper electrician does an eicr then I bet all that would be needed to earth the lights is a 4" stub of cable from cobduit backbox to fitting

 

[davesparks]

You can't expect a tradesman to be available at short notice, we don't all sit at home waiting for the phone to ring. We have lists of jobs to do and regular maintainance jobs and big jobs booked months in advance.

If an electrician isn't busy it's because nobody wants them doing their work!