Has anyone had experience of green goo in their house wiring? Did you rewire on discovering it? Did it ever reach the point of failure?
If you’re not familiar it’s specific to wiring made in the late-60s where a plasticiser additive in the PVC insulation eventually decomposes, reacting with the copper and leaking out as green goo. And “green goo” does seem to be the accepted term for it!

We’re partway through a full renovation and have discovered traces of this through most of the house. I think it’s generally accepted that it’ll become unreliable eventually, but isn’t dangerous. Several electricians have looked at it and nobody’s suggesting we need to take action (yet), but neither are they willing to stick their neck out and give an estimate for how long long it’ll last. It could fail in the next 2 years, or it might last 10 trouble free.

We elected for a full wire downstairs as we were just about to do the kitchen, and more than anywhere that’s the room we wouldn’t want to rip apart to fix issues later. That was messy as hell and we still haven’t finished patching up all the wall and ceiling chasing.

But we still have 3 bedrooms and a living room split across 2 floors upstairs to think about. We’ve laid a hardwood floor on one of those, and plastered a few walls in 2 others. The floor is non-negotiable – we’re definitely not lifting that for now – but we plan to lay flooring in the other 3 rooms too. Costs aside, now would be the most practical time to do such work, whilst we’ve got bare floorboards for easy access and 2 rooms of unpainted walls and ceilings.

It’d be bloody annoying to lay more floor and then have to lift it a couple years down the line. Equally, we could really do with not spending several £ks on rewiring now if we can help it. Any experiences to share?

No idea about it, but if you’re gonna do it, do it now.

It may be a hassle etc just now but it’ll be even more disruptive in XX many years time.

So you except that you will need to have it done eventually and that it will be more disruption and therefore more Money if done in the future. The question you need to answer is if the extra expenses and disruption is worth the delay. Let’s say it cost £1k more and causes 1 week of disruption in 1 years time when it becomes unreliable. Is that gain of one year delay something that you would be willing to pay £1k and one week of disruption for?

If it was my house and If I could afford it, I’d do it now.

I’d rather do any job(s) in one big go.

My wife would rather do lots of little bits.

In my mind thats one:
-Plaster/ plastering quotes. Will the plaster who you get now still be available in 10 years?
-set of decisions as to what to repaint. Will the exact shade of paint be available in 10 years if a room rewire has to go into the hall?
– trip to the shop to buy all the paint
-one set of gear to paint in.

5 years on from my last full project:
-The roofer won’t answer his phone
– the electrician won’t do any heavy lifting or tricky stuff
– the plumber has more or less doubled his rates
– the builder has moved to Hungary, then back, then stopped answering his phone.
-wikes has changed the brilliant white trade mat veeeeeery slightly so it’s whole walls and no wee touch ups.
– the joiner has retired
-the window fitter had gone back to working for a company and doesn’t do any installs on his own any more.

Soo all the effort of finding a crew of people who do a decent job, at a decebt price who turn up when they say they will has to be repeated.

On the other hand, it gives you time to save, time to find out exactly where you want things like light switches and sockets. How many sockets do you need…..

Also, what if it sets your house on fire? Is it worth it for peace of mind?

How friendly are you with the electrician that did the downstairs?
If you can find one that’ll sign off on your work then there’s no reason why you can’t run the cables, cut chases, etc. ~£100 for cable, back boxes, etc and you don’t need to connect anything if you don’t want to. Another ~day to connect and test
The goo is conductive, although the plsticiser on its own isn’t, and suggests a problem in the installation apart from the obvious gunge. Google green goo if you haven’t already

Whenever I come across it I recommend a rewire and I won’t work on the existing wiring either. It’s the pvc insulation breaking down so there’s going to be faults occurring on the installation eventually.

1960s wiring and your are 50/50 about replacing it?

I’d be doing it as a priority at the expense of something else.

1960s wiring and your are 50/50 about replacing it?

This.

If you have the money to do it now, do it now

Yep agreed, I’d be doing it now whilst other work was ongoing. Lots of potential issues with reusing that wiring. Best case scenario your RCD keeps tripping out on circuits, worst case scenario you have an electrical fire.

Even if I had to use the credit card to do my shopping and stuff for a few months to free up cash I’d be doing it.

Wiring. Do the floors later when you have the money*

Anything else is madness and double work – probably double cost laying your hardwood floor twice – may even end up buying it twice dependant how your fitted lays it

*We had the same issue- don’t regret scrabbling round to pull the money together and not having a nice floor /walls for a while. Took me 2 years to get the funds to get to the point of being ready in terms of finish and funding a plasterer.

Pretty conclusive then!

To be fair, until about a week ago we were dead set on doing it now. But have just started looking around hopefully for short term savings. I think that’s a clear ‘no’ for this one now!

We were fairly happy with the electricians we used, but didn’t manage to get a proper comparison of costs as we needed a quick turnaround to get someone before our kitchen fitter was booked in. So no real idea if they’re overpriced or not!

We had 3 electricians look round, spending an hour each discussing all the details and only 1 of them returned a quote. We chased one of the others pretty hard too, but still no response. We’ve had the same with a few other trades, which I’ve never understood. At least high-ball us a quote and then you’re quids in if we take it, and getting something in return for that hour of time!

I’d ask you to read this https://uk.prysmiangroup.com/media/news/green-goo especially the last couple of paras starting, “If, however, it is considered that rewiring is not required…”
They manufacture cables so their science will be sound

They manufacture cables so their science will be sound

Will they pay to repair if/when the faults start coming.

I mean why do half a rewire Either it was required or it wasn’t…..

Will they pay to repair if/when the faults start coming?

They’re saying periodic inspection and testing which implies a qualified electrician
This will include insulation resistance between conductors to detect a low resistance and the possibility of a short circuit
Insulation resistance is tested at 500V d.c. and needs suitable kit, you can’t do it with a normal multi-meter
Conductor resistance is important because too much will cause heat which will break the insulation down lowering insulation resistance between conductors so that you get the possibility of a short circuit
As to the periodic bit, “no established guidance exists”. I think that you’d struggle to find a qualified electrician who’ll stick their neck out on this. If you could, a periodic inspection at say £250 a time every 6 months soon gets expensive for no benefit

I mean why do half a rewire Either it was required or it wasn’t…..

Agreed, but the decision was made because they didn’t want to knock the new kitchen about to rewire. If everything tested okay at the time then that’s it. A date will have been put on the certificate for next inspection but there’s no legal requirement to test. You can bet that the house insurers will have an opinion

Lots of melodrama in this thread…..

E.g.

I think that you’d struggle to find a qualified electrician who’ll stick their neck out on this. If you could, a periodic inspection at say £250 a time every 6 months soon gets expensive for no benefit

As opposed to doing what could be, in the absence of a legal requirement, considered “best practice” and getting an EICR done for ~£70 every 5 years?

Guess it boils down to how long you see you living in the house you’ve bought.

For me it was long term so why wouldn’t you do the intrusive work at the start.

Sure as shit you’ll cut that corner – get the house nice …and then bam

EICR done for ~£70 every 5 years?

NICEIC say 3-4 hours. That’s probably a test looking at a small percentage of sockets and switches, etc. £125 for an electrician, £80 for an EICR specialist
Do you know where the “green goo” will appear? I’d be looking at 100% of cable ends, lifting floorboards, going into the loft, cleaning and replacement as necessary. Will the EICR specialist do the work at that price? YMMV, but I wouldn’t be taking the job on
Five years in the case of a sound rental property, but how long do you give a property with deteriorating cable insulation?

Love it, £100 for cable for a rewire and £75 for an EICR. Maybe in the 1970’s 🤣
A good EICR that’s worth more than the paper it’s on is at least £200 on an average 3 bedroom house. Any less which you can find easy and it’s a box ticking exercise full of limitations that could be torn apart by anyone qualified and experienced.

As for the green goo get it out now while it’s cheaper to do.

in the absence of a legal requirement, considered “best practice” and getting an EICR done for ~£70 every 5 years?

Does anyone actually do this for a residential property?

Its just the additive reacting withthe copper. It won’t cause a fault unless the insulation starts corroding. Maybe if it caused a short circuit but that’s highly unlikely.
Having said that, it’s obv cheaper and easier to rewire on a building site than a nice house with new carpets etc. I’d say as long as there are no leakage issues and the cables are in good condition, it would easily last another 20 years.