by ericmark »
Thu Jan 21, 2021 1:01 am
Parents house built 1954, wooden back boxes for light switches with MK marked on them so clearly at that time made of wood.
Rules changed in 1966 on earths to lights, before then not required, parents house was wired in 7/0.029 which in modern day is 2.9 mm² where today we use 2.5 mm² for the ring final. But it was not PVC but rubber and in some places the rubber was a bit worse for wear.
Even some early PVC cables the plastersizer leached out, often as a green grunge and it left the insulation rather brittle and likely to crumble if touched.
The Wylex fuse box was common at the time, with re-wireable fuses, because it was easy to fit wrong size wire, these were discontinued with either cartridge fuses or MCB's and you can still buy the MCB's to replace the wire fuses.
But that was not the end of it, back then it was common to use the water pipe as an earth, since I remember blowing a fuse as a lad when I let a live wire touch the chassis of the tape recorder I was mending, I know it must have had an earth, but in 2004 when I came to work on the house, found no earth, the metal water pipes had been replaced with plastic, so by-by earth.
Some one had actually taken the GPO earth used for old party line phones and connected that up, but the connecting wire was well under size.
Dad refused a re-wire, did get the fuse box changed to a consumer unit around 2004, but the RCD would not hold so a isolator fitted, dad said I am not living in a building site you can rewire it when I'm gone. And that is what we did, it was brought to a head when mother put an extension lead in a bucket of water when she thought it was on fire.
I had the minimum done, I was not sure what was going to happen, rent the house to pay for her care home, or we would move in with her it turned out the latter. So cost around £2500 in North Wales. Not full rewire as kitchen and wet room already done.
And I at last stopped worrying, I had to make good, but I had a completion certificate so could rent out if required, it never was required, when she died house sold.
So it seems you are in a similar position, but you may be lucky, but the house buyer survey as I found out with this house, is not an electrical installation condition report (EICR) and one has to ask with wiring that old is it worth having one done, or just re-wire anyway?
An electrician with have two meters, a clamp-on meter which can measure down to 0.001 amps, and an insulation tester, and can tell you if fitting RCD's if they are likely to trip. Just banging in a new consumer unit instead of a fuse box is a bad move, without testing first.
But likely until re-wired you will not be able to add anything to the existing installation, as although not retrospective anything new will need RCD protecting.
