I believe the early plastic-PVC type of cable came out 70 years ago, and there's a lot of that still around in excellent condition.
Confused about a rewire.
- Thread starter VictorianModern
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One reason PVC cable may need replacing is if it has been touching polystyrene insulation, which attacks the cable sheath and no doubt the insulation eventually.
If the cables aren't cooked by overloading, you'll be fine. If they aren't exposed to sunlight, you'll be fine. If the EICR says it's ok, believe it.
Of course, if you start pulling higher currents, plugging in more things, allowing mice to have a nibble ...
What you may want to think about i if you have enough sockets in the right place, or the light switches are where you want them etc etc. That might be a better trigger for a rewire than just age.
Of course, if you start pulling higher currents, plugging in more things, allowing mice to have a nibble ...
What you may want to think about i if you have enough sockets in the right place, or the light switches are where you want them etc etc. That might be a better trigger for a rewire than just age.
Yep, I think it appeared about 1950 - but my "50-60 years" was thinking about when it would have been fairly widely deployed - and, as we've both said, still doing fine.
Kind Regards, John
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In all my years, I have come across one installation that intrigued me. I still can't find any information about the cable, but know now what it is made with as they used the same brand name for plastic pipework.
I came across a house built in the 50s with cable marked "Alkathene". I now know this is MDPE.
IME, the oldest cable type I have seen is rubber insulated singles, covered with a braided cotton sleeve. These were feeding round pin sockets with a separate solid earth. The singles were in a mitred moulded wooden trunking. Fantastic workmanship!
Then lead-sheathed rubber insulated twin cable, the lead sheath having clamps attached to earth.
Then rubber twin and earth, with twin only for lighting.
Then rubber twin and earth for lighting, pulled out of a house built in 1956. 10 years before its time?
Then the afore-mentioned Alkathene cable.
Then PVC, the early 70s production produced a green goo.
I have also come across a few blocks of 60s/ 70s flats where I found aluminium twin and earth in larger CSAs than their copper counterparts.
A drive to produce an alternative when copper was extremely expensive?
I came across a house built in the 50s with cable marked "Alkathene". I now know this is MDPE.
IME, the oldest cable type I have seen is rubber insulated singles, covered with a braided cotton sleeve. These were feeding round pin sockets with a separate solid earth. The singles were in a mitred moulded wooden trunking. Fantastic workmanship!
Then lead-sheathed rubber insulated twin cable, the lead sheath having clamps attached to earth.
Then rubber twin and earth, with twin only for lighting.
Then rubber twin and earth for lighting, pulled out of a house built in 1956. 10 years before its time?
Then the afore-mentioned Alkathene cable.
Then PVC, the early 70s production produced a green goo.
I have also come across a few blocks of 60s/ 70s flats where I found aluminium twin and earth in larger CSAs than their copper counterparts.
A drive to produce an alternative when copper was extremely expensive?
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@winston1 On this occasion, I apologise for my over- reaction to your post.
I agree that it is possible for PVC cables to last as long as 100 years.
Accepted.
Well Winny's had a word, Taylors had a word, John's had a word and now it's my turn.
Plastic T&E (and for that matter twin[without earth]) has been around for close to 70 years, or so I believe.
I know of a row of a dozen or so homes with garages added in late 60's in the back gardens. Each garage has been powered with imperial PVC T&E clipped to fences, suspended on cateneries etc and being HA properties have to be inspected. To date, other than one 7/0.029" being repeatedly overloaded, I believe only one has 'failed' in 50+ years and that had ended up being buried, partly under patio and the rest (~20m) a few inches down in flower border/lawn.
I'm not convinced many of those feeds will survive another 50 years but of course we no longer consider T&E to be an outdoor cable.
Moving away from those properties, I certainly know of a house predating 1961 wired in plastic T&E which still has some of it's original cable in place and is still satisfactorily passing inspections. Stripping it feels more like polyethyline than PVC which I assume is asathene (but I'm not a plastics expert).
It doesn't feel like it's going soft or hard, it's not going sticky, it feels totally stable. As it is I feel there is no reason it shouldn't last another 40 years.
Alterations there are done with PVC and my thoughts remain the same.
Generally I have to agree PVC cable is likely to last a long time, 100 years if installed correctly. However some of the very modern cables feel... let me use the word 'rough' start looking shabby quite quickly which makes me wonder if they are getting contaminated and likely to have a shorter lifespan.
Quite. Indeed, as I've reported before, a few years ago I took out of service (for no reason other than that I had 'found it'!) some early PVC cable (30m or so) that had been buried directly (without any protection) in my garden for at least 40 years, probably a lot more, and was,both visually and by testing still fine when I removed it.
Possibly, but I somewhat doubt it. On the contrary, I would suspect that modern PVC cables are, in general(ignoring and 'rogue' ones) probably 'superior' than those of 50+ years ago - so I continue to suspect that the 'modern' ones will (if not mechanically damaged) remain fine for at least 100 years, perhaps a lot longer (if they are 'allowed' to!).
Maybe there are things which I don't know/understand but, on the face of it, I can't see any good reason why anyone other than those wanting to sell cable would have a reason for even dreaming of advising routine replacement of PVC cable after anything like as little as 25-30 years in service ... but that's just my thinking, and I am not beyond being a little cynical
Kind Regards, John
The reason I came up with that thought process; I have lots of 0.75mm² 2 core oval flex used for temporary loudspeaker leads (PA systems), some of which is more than 60 years old, but most hails from 70's. Having a sort out recently I dumped the remains of 300m which was the most recently purchased (specifically white for use on a job with white paintwork). I was always the least flexible, the least smooth surface, got very dirty very quickly and didn't wash clean but most specifically cracked/split with constant coiling/twisting etc.Quite. Indeed, as I've reported before, a few years ago I took out of service (for no reason other than that I had 'found it'!) some early PVC cable (30m or so) that had been buried directly (without any protection) in my garden for at least 40 years, probably a lot more, and was,both visually and by testing still fine when I removed it.
Possibly, but I somewhat doubt it. On the contrary, I would suspect that modern PVC cables are, in general(ignoring and 'rogue' ones) probably 'superior' than those of 50+ years ago - so I continue to suspect that the 'modern' ones will (if not mechanically damaged) remain fine for at least 100 years, perhaps a lot longer (if they are 'allowed' to!).
Maybe there are things which I don't know/understand but, on the face of it, I can't see any good reason why anyone other than those wanting to sell cable would have a reason for even dreaming of advising routine replacement of PVC cable after anything like as little as 25-30 years in service ... but that's just my thinking, and I am not beyond being a little cynical
Kind Regards, John
I know flex and T&E are not handled in the same way which makes it difficult to compare them.
Fair enough, but ....
That's the point. The context of this discussion is in relation to the 'fixed wiring' cables of an installation, and they are not subjected to "constant coiling/twisting etc." or any other form of mechanical disturbance/stress and are rarely subjected to UV radiation (and most never get near their 'maximum operating temp'). Those are the cables I was talking about
I would never suggest that 'flexible' cables that were constantly coiled/twisted/handled/goodness-knows-what (being 'trampled upon' etc.!), and quite possibly were often exposed to UV, would be likely to remain in satisfactory condition "for 100 years"!
Kind Regards, John
My point is the sheaths of the modern T&E and that flex feel very similar and both got dirty/contaminated in the same way, just as older T&E and flex has, so I don't think it's unreasonable to make a comparison. Obviousely I'm unable say with certainty that newer T&E will not have the same long lifespan. Newer white T&E does discolour with light (presumably UV) quite quickly though.
Emboldened for sanity.
Sure, there can be no certainties but, for what it's worth, my personal suspicion is that differences between older and newer PVC cables are unlikely to impact the life expectancy of fixed wiring cables which are virtually never 'disturbed' and very often (literally) 'never see the light of day'.
Kind Regards, John
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