Maximum age of wiring

[benwyatt]

Hello,

I live in a house where part of the wiring dates to 1960 (exact). Now I know after ~30 years old, a rewire is advised. And at 58 years it should definitely be rewired, but it's going to be difficult to convince my parents to have the house rewired soon - as we have 5 people living here and it's going to be expensive.

What do you think is the absolute limit you can have with age of wiring? To the point it turns from strongly advised to must happen, i would like to know this to get an idea of the amount of time ticking left until it becomes too dangerous to use.

Thank you

 

[Strima]

I would recommend that an EICR is carried out to ascertain the state of the installation.

Only then can you tell what condition it is in. At 58 years old it could very well be in good condition and fit for another 58 years, unless DIY Bob has been at it.

 

[NDG Elecs]

It's hard to give a definitive answer because to some extent there isn't one really. PVC cables can last a long time, but there are many variables that can affect it. If cables are consistently used close to their limit over many years this would likely serve in reducing their lifespan, whereas cables that are hardly loaded for many years will probably last a good deal longer. Other factors include the standard of the materials used when the cable was manufactured and other influences such as environmental ones.
I have tested old aluminium cables (which I understand were around in the late sixties due to copper prices rocketing) and the results have been very good indeed. Not withstanding the fact that copper is the preferred choice of conductor.
There used to be rules of thumb (as you describe) for the life expectancy of cables, but with modern cables the intervals are probably not as prescriptive.
Your best course of action would be to get a full and thorough EICR carried out. This would give an indication as to the state of the wiring hidden in walls and under the floorboards etc. You may end up pleasantly surprised. Although you may end up aghast also!!

 

[plugsandsparks]

Re-wire when cables do not meet insulation resistance tests.
Re-wire when cables dis-integrate when trying to replace a light fitting or switch.
Nice to re-wire when the existing wiring does not meet the requirements for lights, sockets and other appliances.
Age of wiring is of interest but as wiring can age very differently depending on its environment, there is no must after a certain time.

 

[PEG]

Yep,thorough testing and a good visual inspection,done by somebody capable and trustworthy,is in order.

I know of many installations beyond the age you have mentioned,where the installed wiring tests A1,and a visual prompts no concerns.

The only exception to this,is when BG are involved...

 

[Octopus]

Cables installed after the mid 1970's do not need replacing after 30 years.

 

[benwyatt]

Hello and thank you for the replies.

I have done (sort of) a visual inspection myself. All the backboxes have 4 holes for screws rather than two. The cables are solid core, rather than stranded. The earth cable is not insulated except in the backbox itself with solid green insulation. Light switches have no earth, the new bathroom has brand new wires. Will I have to check in the loft to see if those brand new wires go all the way back to the CU? I'm worried that they could've been connected to the unearthed 1960 cable so there's no 'continuity' (if that's what you call it?). All sockets are the newer but old square MK ones.

All the cables that I have seen, just look like normal cables and aren't deteriorated, which is good.

One thing is, there's aboht 5 spurred sockets (in the 60s part of the house) to meet the demands of the appliances we use, is that a concern? Will the original cable normally handle the spurs? There's a whole other part of our house with newer wiring I'm not concerned about, but I haven't checked if it's on the same socket circuit for example. Would that be a problem?

The last inspection was in summer 2008, so I think another one is due anyway.

Thank you

 

[MJPD29]

It may be Ok, a bit of a stretch at 58 maybe but get an EICR done and then you will have a better idea as it may well be ok

 

[Octopus]

PS there was no requirement for earths (cpc's) on lighting circuits before the mid 1970's

Deffo an EICR and a live in rewire would not be ideal .......

 

[telectrix]

agree with the several posts on get an EICR done. only way to see what condition the installation is in, and whether or not any remedial works are needed.

 

[PEG]

PS there was no requirement for earths (cpc's) on lighting circuits before the mid 1970's

Deffo an EICR and a live in rewire would not be ideal .......

Yep,my folks house was built 1963,and although wired in good quality t&e,they had clipped all the cpc's off

Rectifying that issue correctly,was still considerably easier than a rewire. Their electric underfloor heating still continues to function and pass all tests,which puts to shame some of the new systems,failing at tender ages

 

[telectrix]

Yep,my folks house was built 1963,and although wired in good quality t&e,they had clipped all the cpc's off

Rectifying that issue correctly,was still considerably easier than a rewire. Their electric underfloor heating still continues to function and pass all tests,which puts to shame some of the new systems,failing at tender ages

underfloor heating in manchester? you'll be getting mains electrickery next.

 

[Andy78]

PS there was no requirement for earths (cpc's) on lighting circuits before the mid 1970's

Deffo an EICR and a live in rewire would not be ideal .......

1966 I thought ?

 

[Des 56]

Try not to be ageist

The system will not have standards that are now in force regards regulation changes since it was installed (that does not imply lack of safety)

If the system has not been messed up by "householder knows what he's doing" botches or stressed by heavy use,then you may even look forward to a bonus 60 years

You can also take advantage of enhanced safety features now current by upgrading to comply with these current regulations without the disruption of rewiring

 

[Dave OCD]

I did a CU change last week in a bungalow built in 1968, unusually the original installation has remained unmolested with all the original bombproof [at that time] MK accessories still in place. Every circuit tested out really well, lovely old imperial stranded cable with tinned conductors, the only other thing I had to do was sleeve the CPCs at the new board and put a new main earth in, all of 600mm of 16mm cable.

 

[driverman]

Agrees with above comments. Have an EICR carried out.
I not too sure about any actual time span given for cables.
Many years ago 25 years was a given guideline for rubber cables. Some didn't get there, others went way past it!

 

[NDG Elecs]

1966 I thought ?

Yeah I have 1966 in my head too. If that is incorrect I would like to know.

 

[NDG Elecs]

1966 I thought ?

Bloody duplicate again....

 

[davesparks]

I have done (sort of) a visual inspection myself. All the backboxes have 4 holes for screws rather than two. The cables are solid core, rather than stranded. The earth cable is not insulated except in the backbox itself with solid green insulation. Light switches have no earth, the new bathroom has brand new wires. Will I have to check in the loft to see if those brand new wires go all the way back to the CU? I'm worried that they could've been connected to the unearthed 1960 cable so there's no 'continuity' (

The number of holes in the backboxes has no relevance to the safety of the installation, but it will almost certainly mean they use imperial threads rather than metric.
We still commonly use solid core cables for lighting and small power in domestic installations.
The earth in a modern T&E cable is not insulated and would only be sleeved where the cable is stripped for terminations, the only difference is that we use green and yellow stripes now.

Yes a lack of earth in the lighting circuits is a safety concern and should be rectified when possible. Be wary of people advising that an RCD and a yellow sticker are a suitable alternative, they are not!