Concrete flat rewire!
- Thread starter petearm
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I went recently to a building that was wired in mineral the year my mum was born and it's still going strong!
Oh, it was 1936, btw!
It sounds like you need to find a better electrician.
See if you can find one who has experience of conduit systems. Probably someone who also does industrial installations would be a good place to start.
Mineral cable should easily last 50 years if it's been installed properly, and I'd guess maybe 100 / 150 years. Who knows. It's not been around long enough to find out yet.
See if you can find one who has experience of conduit systems. Probably someone who also does industrial installations would be a good place to start.
Mineral cable should easily last 50 years if it's been installed properly, and I'd guess maybe 100 / 150 years. Who knows. It's not been around long enough to find out yet.
Did you actually try and split the circuit up and test it? You could be doing a lot of unneeded rewiring for a few bad pots.
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Hello all,
My girlfriend and I have clawed our way onto the property ladder by buying a 1 bed flat. It's all concrete and the ring mains and lighting circuits are run through conduit. The wiring is pretty haphazard throughout with one spur running through the plaster with no earth! We also need to install heating and want an economy 7 system with fan assisted storage heaters. For the above reasons we have decided to get the place rewired.
Depending how the cabling for the heaters will run, you will end up with far more cabling density in the flat. Heaters in recpt, bed, hall will add 3 x 2.5mm or 3 x 4mm (load, run, method ???).
If your rewiring add in TV co ax, data and voice cables.
I'd suggest you board out a main room and use the gaps 'created' behind to run every thing in, certain cables could be back to backed (say sockets and heaters for rooms on the other side of the walls). This means boarding should be restricted to one full room.
All the other rooms feed from the boarded room and there's are easy cheats like having a wall light in the hall and bathroom, thus no surface cabling (because it's run on the boarded sided of the room).
Fully boarding a wall, tape and seam fills (rather than board / tape / plaster) isn't that expensive £300-500 plus materials, or DIY / mates. Just plan for doors and windows when adding in boarding.
Probably - although in most instances you won't need to pull them out. Remove a light fitting and the switch for it, and by carefully pulling on one end of a wire at the switch it will be obvious if it is stuck or not - you will be able to see the other end at the light fitting.
If the wire moves, then it's 99% certain you can pull new wires in.
Cutting into the ceilings or floor is no use - they will be structural components so don't even think about cutting into them.
That 'coving trunking' is all very well, but you could just as easily clip the wires to the wall and put normal coving over it for a fraction of the cost. It will also look far better as coving is designed to be painted, unlike that plastic stuff.
Another option which will be far better for the sockets and heating cables is to replace the skirting with square edged boards, and put quadrant surface trunking directly above it. With careful installation of the boards, they can be set so the front edge of the board is flush with the edge of the trunking, so you will hardly notice it.
Unless the walls are really bad (plaster literally falling off), you can put the new boards straight over the existing plaster.
Any cables can simply be clipped to the existing wall before the new boards are put on.
1965 would suggest a proper half inch complete conduit system. This will have been designed to be re-wired. That is the whole point of circular conduit. These conduits should allow for a like for like re-wire. If the conduit is metal there may not be a separate earth wire, but there should be space to add one if your electrician wants to.
If your flat was built a good while before this, say the 30s, a different type of conduit may have been used, where the wires were put in as the conduit was assembled. This cannot be rewired completely. Since you say 1965 it is most unlikely you have this.
It is likely you will need extra wiring to meet today's requirements. Take advantage of fitted cupboards to accomodate additional wiring.
If you cannot use the old conduits, or they are in the wrong place, fitting a false ceiling would be a good solution. This would also allow you to have recessed spotlights if you are so inclined.
Fitting plaster coving is also a good way to hide cables without having naff looking plastic coving/skirting trunking.
Dot and dabbing the walls will be a disaster as the skirting boards and architraves will have to be removed, and the door linings will have to be made wider and the doors rehung.
Re-use as much of the conduit as you can.
If your flat was built a good while before this, say the 30s, a different type of conduit may have been used, where the wires were put in as the conduit was assembled. This cannot be rewired completely. Since you say 1965 it is most unlikely you have this.
It is likely you will need extra wiring to meet today's requirements. Take advantage of fitted cupboards to accomodate additional wiring.
If you cannot use the old conduits, or they are in the wrong place, fitting a false ceiling would be a good solution. This would also allow you to have recessed spotlights if you are so inclined.
Fitting plaster coving is also a good way to hide cables without having naff looking plastic coving/skirting trunking.
Dot and dabbing the walls will be a disaster as the skirting boards and architraves will have to be removed, and the door linings will have to be made wider and the doors rehung.
Re-use as much of the conduit as you can.
"Disaster" is a hell of an exaggeration.
Yes, and then replaced. Replace with new rather than re-use the old is not exactly a labour of Hercules.
No and no - assuming it's painted wood.
Remove the architraves, and before fitting the plasterboard, rub down the existing linings to bare wood, or almost, and then screw and glue some nice PAR pieces in to bring the linings up to plasterboard level. Filler as necessary, repaint, and you won't see the joins
Cutting chases into a wall, fitting coving and even asking for a new lowered ceiling is one thing.
But asking for dot and dab everywhere and a total rethink on the woodwork is quite another.
From a rewire it will have developed into a major plastering job and a major woodworking job.
Not many customers would expect or be prepared for that kind of work or expense, unless they are doing drastic modernisation.
The majority of the new wiring should be run in the existing conduits if possible - this is the whole point of conduit.
For 1965, the plaster should be in good condition anyway. I would expect it to be rock hard and not crumbling. It could of course be very uneven and knocked about after all these years.
I have never asked anyone to dry line an entire/vast majority of a flat. I have always found a way that is in line with all regs.
Dot and dab is inferior anyway. You don't get such a good fixing when fitting cupboards. Worst of all it makes the rooms a bit smaller.
But asking for dot and dab everywhere and a total rethink on the woodwork is quite another.
From a rewire it will have developed into a major plastering job and a major woodworking job.
Not many customers would expect or be prepared for that kind of work or expense, unless they are doing drastic modernisation.
The majority of the new wiring should be run in the existing conduits if possible - this is the whole point of conduit.
For 1965, the plaster should be in good condition anyway. I would expect it to be rock hard and not crumbling. It could of course be very uneven and knocked about after all these years.
I have never asked anyone to dry line an entire/vast majority of a flat. I have always found a way that is in line with all regs.
Dot and dab is inferior anyway. You don't get such a good fixing when fitting cupboards. Worst of all it makes the rooms a bit smaller.
Turn the flat decor into a mock Tudor appearance with dummy posts and beams to conceal the cables.
Did you actually try and split the circuit up and test it? You could be doing a lot of unneeded rewiring for a few bad pots.[/quote]
Yes spent Saturday afternoon sub dividing the lighting loop and testing the 'sum of its parts' was getting some infinite IR tests but also still getting some low ones in a few rooms.
The client is going to get his builders to do all the chases.
Just packing up my tools another resident asked me to have a quick look at his installation and unlike the current one which has it's own service cut out, this one was fed in what looked like 10mm pyro. Which I have never encountered before.
Yes spent Saturday afternoon sub dividing the lighting loop and testing the 'sum of its parts' was getting some infinite IR tests but also still getting some low ones in a few rooms.
The client is going to get his builders to do all the chases.
Just packing up my tools another resident asked me to have a quick look at his installation and unlike the current one which has it's own service cut out, this one was fed in what looked like 10mm pyro. Which I have never encountered before.
Turn the flat decor into a mock Tudor appearance with dummy posts and beams to conceal the cables.
or wainscot panelling.
Although fitting a false ceiling is probably unnecessary (the existing conduited light and switch points are probably in about the right places and meet essential needs, unlike power wiring of 1 socket per rooom) a false ceilign with some insulation above would probably make a concrete flat a lot wamer and more comfortable.
So in the end we used the conduit for the lighting circuits and put minitrunking behind the coving and chases down to the new power outlets. The conduit was in good condition and there was plenty of space to run an additional earth. However the ring main conduit would have struggled with cables for storage heaters hence the mini trunking.
Thanks to everyone for the advice, if I hadn't heeded it I would probably have allowed the first sparky who came along to run chases through all the ceilings with unknown structural consequences not to mention mess!
"Turn the flat decor into a mock Tudor appearance with dummy posts and beams to conceal the cables. "
This was my favorite suggestion, unfortunately my remit doesn't include interior design..
Thanks to everyone for the advice, if I hadn't heeded it I would probably have allowed the first sparky who came along to run chases through all the ceilings with unknown structural consequences not to mention mess!
"Turn the flat decor into a mock Tudor appearance with dummy posts and beams to conceal the cables. "
This was my favorite suggestion, unfortunately my remit doesn't include interior design..
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