Is there such thing as a 'partial rewire'?

ChasingtheWelshdream

I'm sort of thinking out loud....

We are adding an en-suite and will need the electrics sorting for the light and extractor fan so need to start talking to Electricians. We would also like a couple of sockets added to the living room.

Now our house is Edwardian and has had all sorts of bodges over the years. The consumer unit is only 6 years old (we have the certificate), but the rest of the electrics are a mixture of modern switches & sockets, older toggle switches (possibly bakelite), a couple of defunct/dodgy sockets (either not working or too suspect to use, as in a bit loose) and not a few random blanking plates dotted around. There are even light switches on the skirting that appear to serve no purpose, they've just not bothered us enough to investigate further - behind the sofa, out of mind.

So some electrical work or testing has happened when the consumer unit was replaced, and I would hope that anything dangerous would have been flagged up then. What I'm wondering now, is whether an Electrician is likely to be happy working on specific circuits only to add the extras we need, or whether they would insist the whole system needs re-wiring before they'll touch anything.

As with the heating system, we have no doubt complete renewal would be ideal, and if budget allows then now would be a good time whilst we have bare plaster/floors etc.  If however the cost is prohibitive at present, can electrics be re-wired piecemeal as and when funds allow? We're 5 bedrooms over 3 floors so I would imagine a fair chunk of cash to do the lot in one go.

Obviously we'll discuss all this when we get quotes, but I like to have an idea of possibilities beforehand. If someone says it's 'all or nothing', then I hope I'd be able to better judge whether it's a genuine reason or trying a hard sell.

I'm probably not making much sense....

ChasingtheWelshdream

In a nutshell - if the specific circuits we want sockets/lights added to are found to be unsafe, is it acceptable to only have those ones rewired? Or is it a case of everything or nothing in terms of building regs?

If we can stretch to a rewire, we will. We may even be able to save on labour by chasing the walls ourselves (yep, I know the mess will be horrendous). But I'm mulling over all scenarios.

Davesnave

We were rewired piecemeal over 3  years as our renovation progressed, because we kept knocking down walls and destroying bits of the previous circuits. However, we had the ability to bodge stuff together temporarily as and when required, so we weren't calling the guys out all the time - an impossibility here anyway with mobile signals as they are/were!

Also, as our guys were mostly into commercial work, they used us as fillers for odd times between bigger jobs, whereas another firm, seeing what we planned, priced for disruption at nearly £9k for a full rewire on a normal large bungalow! Obviously, they didn't want to know.

Best thing is to talk to local sparkies and see who you think you can work with. Our final bill came out at around £5k.

silvercar

We have a similar set up.
When our extension as built (by previous owner), they put in new electrics obviously and took that back to a mini CU that feeds off the main CU. So we know that part of the house is fine and presumably they managed to do that without any issue.
We replaced the CU 10 years ago, so it is fine, but we do have bakelight switches that run off it and I think that a few of the light fittings aren't earthed.
So basically, I think you could get away with new stuff and replacing the areas that you need to do so, without doing a full rewire.
You may find that the random switches are no longer connected to anything at all and therefore don't form part of your electrics. Call them (un-)decorative fittings!

ChasingtheWelshdream

Thanks Dave and Silver, that's reassuring. I had visions of having the electrics condemned somehow and be forced to upgrade everything. My mum wanted a socket added and the Electrician wouldn't do it because he said he couldn't sign the work off without upgrading something else  I'm not sure what it was but I was worried we'd be in the same situation.

We could allow £5-6k for a re-wire by culling our wish list elsewhere, but much more than that and we'd be short to do the main work we want. On the other hand, we've borrowed money in order to actually finish the house so does make sense to get what we can done. You've reminded me that when we knock through a wall the light switches and existing sockets are going to be in completely the wrong place too. I think it's definitely time to draw up some very detailed plans before we start talking to trades!

(Davesnave: We had a similar company attitude when we wanted ball park figures for replacing all the radiators. After chasing for a quote we were told "oh, about £11k". Definitely didn't want the job!)

Ectophile

It may make a big difference when the house was last rewired.  If it was any time since the 1960's, then the cables are likely to be PVC insulated, and that stuff seems to last forever if it hasn't been overloaded or otherwise damaged.  You maybe able to get away with fixing any problems, rather than a total rewire.

Prior to the early 60's, various other types of cable were used.  Vulcanised Rubber Insulated (VRI) cable can get so brittle that the insulation falls off it you move anything.  Before that was Paper Insulated Lead Covered (PILC) and cotton insulated.  Anything that old really needs ripping out and replacing.

FreeBear

Ectophile said:  If it was any time since the 1960's, then the cables are likely to be PVC insulated, and that stuff seems to last forever if it hasn't been overloaded or otherwise damaged.

PVC cables in contact with polystyrene is also a problem - The polystyrene leaches the plasticiser out of PVC and causes it to go brittle. Modern PVC cables shouldn't be as prone to the problem, but still a good idea to keep the cables away from polystyrene (and a few other materials).

https://electrical.theiet.org/wiring-matters/years/2019/78-november-2019/pvc-insulated-and-sheathed-cables-in-a-domestic-installation-some-possible-problems/

ChasingtheWelshdream

 Lots to think about, thanks !

kdotdotdotdot

I don't think you'll have a problem finding an electrician who'll do only part of the house for you, but I'd guess that means you won't get the work fully signed off, which can be a pain if you want to sell the house in future.  

I've had my house fully rewired and it's an incredibly dirty business, so if you're down to floorboards and plaster anyway, now's the best time to do it (if funds allow, I get that).  I absolutely no way would want to be doing it once furnished.

Homer_home

kdotdotdotdot said:

I don't think you'll have a problem finding an electrician who'll do only part of the house for you, but I'd guess that means you won't get the work fully signed off, which can be a pain if you want to sell the house in future.  

I've had my house fully rewired and it's an incredibly dirty business, so if you're down to floorboards and plaster anyway, now's the best time to do it (if funds allow, I get that).  I absolutely no way would want to be doing it once furnished.

Its called indemnity insurance , hardly a pain 

lesalanos

"light switches" on skirting boards will possibly be switches for electric storage heaters.

As said above these were probably not connected to the new consumer unit when that was replaced.  Easy enough to check