Rewiring a flat (apartment) with concrete walls

Question

I've just had an electrical check done on my flat, and it's failed. The consumer unit is ancient, with actual fuses, and no RCDs, and the mains sockets don't have earths. Apparently the pipework that holds the cables would have been the earth when originally installed, but owners before me have replaced single sockets with doubles and not properly connected to the piping. So no earths.

The electrician says that it's impractical to chase along/into the walls to do the rewiring, as they are concrete, and this would be about three times more expensive than doing a "surface" job with conduit (which can be made to look "industrial"). The estimate for even the conduit is looking at a few thousand £. (I'm in the UK)

Obviously opinions from strangers on the internet who can't see the property are going to be varied, but I have no practical skills myself.

Does what the electrician is saying at least seem consistent? (It is a small one-bedroom flat in a block that was purpose built in the 1950s or so.)

Answer 1

I would focus on replacing the consumer unit.

Once you have RCDs (or better: RCBOs per circuit), the state of the wiring becomes less critical.

As far as earths, the fact that your wiring was done inside pipes (conduits) is very important. Generally the pipes are installed before the wires are, so it's no trouble installing additional wires (or pulling all the old wires out and replacing with state-of-the-art wires).

Carrying earth on the metal pipe is perfectly fine. Or, a yellow/green earth wire can be pulled into the pipe. Either way is fine.

In fact, the old way of using metal conduits is superior to modern methods. They stopped doing them because new ways are cheaper.

So my advice is to make the most out of the existing conduit in the wall. A variety of surface conduit methods can be used for new outlet locations not currently in the piping network.