1940s house with old clothed insulated wires

RAL238 said:

If you've been able to pull some of the cable into the box that is intact, I would cut off the damaged part and then use these butt splices to attach some new wire to connect to the receptacle.

https://www.homedepot.com/p/Ideal-S...sh-In-Butt-Splices-10-Pack-30-1342S/202894306


The thing that would worry me is what shape is the cable in outside the box, that you can't see?

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The thing is, as I pull more cable into the box that looks better, not only they do not have the individual crumbing conductor insulation, they also have a "seemingly" sound cloth sheathing around the individual conductors. I will snap a picture later.


I said seemingly because there is a chance if I remove the overall sheathing, I may end up chasing more crumbling insulation inside. I don't know. In a few cases, I have found the cable outside that I pulled into the box to be in much better condition, which leads me to conclude those crumble to touch were due to manipulation of the wires.


Of course, the long term solution is to find out how many circuits have this issue, then develop an overall plan. I have found one circuit with new nmb12 wiring, but on the last leg going from one switch to an outdoor sconce had this clothed romex, so that one I just disconnected, abandoned and put a blank cover on. Rewiring is needed once this COVID-19 thing is over.


The butt splice idea I am not sure would help but not eliminate the issue. Because as I remove more and more of the crumbling insulation I have to stop somewhere. If I then connect that end to a butt splice it may work as I make the splice, but if I then push this wire back into the box, that action may cause new crumbles. So I think I need to actually shrink wrap the bare conductor all the way to the intact insulation, then shrink wrap the actual insulation for a few inches, then shrink wrap both with an overlap. The shrink wrap may prevent more crumbling until I do the rewire.

TarheelTerp said:

er, uhm... what's broken about it? What needs to be fixed?

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I don't know what needs to be fixed. That's why when moving into a new place the first two things I do is to change out all water supply stop valves everywhere, and most times the main shutoff that may or may not have been used for years. Then I open each receptacle and junction box to see what's going on, and most times there are some minor changes I need to make. For example just in this house so far:


(1) removed expansion foam. Yes someone at some point decided that they had ants or whatever and spraying expansion foam INSIDE of some the exterior wall boxes, having it stick to every conductor and wire nuts and everything was a good idea.


(2) removed a bunch of GFCI receptacles. There were multiple GFCI receptacles in many boxes due to this cloth romex not having ground. I traced it back to the first in series, and moved it to the load side, which allowed me to use regular receptacles in those old handy boxes which were too cramped to have the boxy GFCI anyways.


(3) Found shared neutrals in some boxes with circuits not on opposing legs at the panel and had to correct for that.


(4) Contemplating changing out all the kitchen's temper proof receptacles, yes I know it's code but they are so much a PIA.


(5) Changing switched receptacles to unswitched, or the reverse.


(6) found clothed romex - which is the reason for this thread.


In general there is probably something to be done to each box I open. I don't know what's behind each box until I open it, and that's why it's a time consuming recon task. So far I have found five buried ground rod around the house too. This also allow me to inventory and map each circuit. Sometimes I am able to balance things out a bit better knowing where each circuit passes through, such as minor rewire to separate out the lighting and the receptacles.

miamicuse said:

I found some cloth romex inside my 1940s house. I have no idea how much of it is there, and I am in the process of slowly opening up every junction box and fixing the wiring as I go.

I am looking for a temporary solution to keep those receptacles in service until I can change them all out.

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CAFCI breaker and you're done.

The reason we worry about ratty old wiring is the potential for it to arc-fault, causing a fire. Without ground the most likely arc fault is a parallel hot-neutral fault. Combination arc-fault breakers detect this nicely.

You can also think about getting dual-mode (combination arc-fault plus GFCI) breakers for human safety, since they only add $10 to the price.

If you positively hate the price of AFCI breakers and you have modern Romex to the first receptacle in the circuit, you can put an AFCI recep there *because AFCI is not mandatory for you*. That is not allowed in cases where AFCI is mandatory.

If I undo the clamps in the back of the metal box, I was able to tease out another 2-3 inches of the wiring into the box, and that wiring seems to be in much shape then the portion inside the box.

.... removed a bunch of GFCI receptacles. There were multiple GFCI receptacles in many boxes due to this cloth romex not having ground. I traced it back to the first in series, and moved it to the load side, which allowed me to use regular receptacles in those old handy boxes which were too cramped to have the boxy GFCI anyways.

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You seem to have a very interventionist style. You want to take it all apart and get your hands on it. When you're dealing with fragile old wiring like this, doing that is a trade-off - you *might* improve things but you'll *probably* deteriorate the wire further in the process.

As such, I say don't bother. Let the AFCI do the heavy lifting, and don't disturb the wire.

So now I have this wire inside the box, with the last 4 inches of it as bare copper because the old insulation has disintegrated.

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And that's why I say "don't disturb the wire". Do as little of that as possible until/unless you are ready to replace the whole cable end to end.

Old Thomas said:

If it works I would leave it undisturbed until you can rewire. You said it has no ground. You can provide a higher level of safety by putting it on a GFCI. Not sure about the latest version of the NEC but a couple of years ago it addressed outlets with open grounds. As an alternative to running ground wires it allowed putting in a GFCI and labeling outlets as “GFCI protected, no equipment ground”. If you have two hole receptacles you don’t need to label because it is obvious there is no equipment ground.
Properly fused and protected by a GFCI it can stay in place till you rewire. You can put a GFCI receptacle beside the panel with new wire to the breaker or a GFCI breaker so you don’t have to disturb remote wiring. You can remove covers and peek in without touching the wires.

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In a previous house I have also protected downstream receptacles with a GFCI next to the panel. I had four circuits I wanted to protect and I just mounted a 4 gang box next to the panel, ran all the wiring for the circuits to the box and back via a 1" EMT conduit. Then installed 4 GFCI receptacles in the new box as the first in series for all those circuits. Worked out pretty good except my wife would ask why I have 4 duplex receptacles next to each other seems totally redundant LOL, and I have to let her know in case something seems to have tripped which receptacle to reset for which. The down side of that is while that is easier to do, I didn't spend too much time finding out what fixtures these circuit served and being old homes having been renovated many times, you have a circuit that goes to the bathroom receptacles, and a hallway receptacle, and the bathroom light etc...and if the receptacle detects a fault at night, both the light and the receptacles cut out leaving you in total darkness. So this time around in this house I would like to as part of this exercise to figure out if I can separate the lighting and receptacle circuits. If it's doable I will do it, if it's prohibitively expensive then I may not.

seharper said:

CAFCI breaker and you're done.

The reason we worry about ratty old wiring is the potential for it to arc-fault, causing a fire. Without ground the most likely arc fault is a parallel hot-neutral fault. Combination arc-fault breakers detect this nicely.

You can also think about getting dual-mode (combination arc-fault plus GFCI) breakers for human safety, since they only add $10 to the price.

If you positively hate the price of AFCI breakers and you have modern Romex to the first receptacle in the circuit, you can put an AFCI recep there *because AFCI is not mandatory for you*. That is not allowed in cases where AFCI is mandatory.

You seem to have a very interventionist style. You want to take it all apart and get your hands on it. When you're dealing with fragile old wiring like this, doing that is a trade-off - you *might* improve things but you'll *probably* deteriorate the wire further in the process.

As such, I say don't bother. Let the AFCI do the heavy lifting, and don't disturb the wire.

And that's why I say "don't disturb the wire". Do as little of that as possible until/unless you are ready to replace the whole cable end to end.

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Thank you. I certainly will keep the idea of the AFCI or even dual mode breakers in mind as part of the strategy. I may end up having to do that but I need to investigate the possibility of rewiring first. One thing to keep in mind, is even AFCI may not be an option here, because I have a fairly crowded electrical panel with 80% of them being GE "slim" breakers, and as far as I know there isn't "slim" versions of AFCI breakers so if I want to go that route, I will just be trading the existing problem with a new one, which is deciding which circuits I should eliminate to make room for a few full size breakers, and that may be a more difficult solution.


At this point I am really kind of stuck between a rock and a very hard place anyway. I have to admit, if it weren't for this COVID-19 stay at home order, I might not have gone crazy and opened every cover plate and do this detailed recon. work which opened a can of worms. But I am already more than half way through, and leaving the old clothed wiring "alone" is really not an option now. As part of the whole exercise, I am fixing what I can as I go. As I opened each box, I had to tease out the device whether that may be a switch or a receptacle to see the wiring behind. I have to get a closer look, to be able to know circuits 10A and 12B pass through this box, circuits 6A and 4B shared a white neutral conductor, circuit 11B is clothed, sometimes I have to take apart a wire nut splice to be able to run a continuity test to confirm if this device is up or downstream of that on a circuit, there is no avoiding the unfolding of these fragile conductors. I have got masking tape labels on most of the boxes now, and that should allow me to map this whole thing out schematically when I am finished. Yes there is a risk (fairly high risk) that the insulation will just crumble to touch and pull, but if I leave every box with this clothed wiring alone, it will not give me the necessary information to do the future rewiring anyway. I need to know there is a clothed wire that runs from box 7 to box 9 up through the attic or crawlspace so when I do get up or down there, I have a pretty good idea what I need to bring to do it, I am not doing multiple crawls just to figure things out. In addition, they have done some rewiring in the past, so the circuits I found clothed wiring, are not 100% clothed wiring, there are "legs" of it in new romex. So far I have found only two circuits with this old wiring, in the same area, so that's good news but I am not close to finished.

miamicuse said:

AFCI may not be an option here, because I have a fairly crowded electrical panel with 80% of them being GE "slim" breakers, and as far as I know there isn't "slim" versions of AFCI breakers so if I want to go that route, I will just be trading the existing problem with a new one, which is deciding which circuits I should eliminate to make room for a few full size breakers, and that may be a more difficult solution.

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I'm glad whoever built your house saved $30 on that service panel... hope he loved those pizzas... but a full panel is an intolerable situation. Since total panel replacement isn't exactly DIY-friendly, I advise adding a subpanel. A stupidly, madly, huge subpanel. Spaces are cheap. I like to see houses have about 50 spaces between main and added sub. A space is what 2 slimlines fit in. You can go with GE if you really want to, but if you have any aspirations for generator in the future, a Siemens main-lug panel is a better choice.

You are right, AFCIs will never exist in double-stuff.

At this point I am really kind of stuck between a rock and a very hard place anyway. I have to admit, if it weren't for this COVID-19 stay at home order, I might not have gone crazy and opened every cover plate and do this detailed recon. work which opened a can of worms. But I am already more than half way through, and leaving the old clothed wiring "alone" is really not an option now.

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When you're in a hole, stop digging

I have to get a closer look, to be able to know circuits 10A and 12B pass through this box, circuits 6A and 4B shared a white neutral conductor, circuit 11B is clothed, sometimes I have to take apart a wire nut splice to be able to run a continuity test to confirm if this device is up or downstream of that on a circuit, there is no avoiding the unfolding of these fragile conductors. If I leave every box with this clothed wiring alone, it will not give me the necessary information to do the future rewiring anyway.

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I've done loads of reverse-engineering circuits from the panel side, in a much worse situation than yours. You do not need to access the receptacles at all. Imagine 11 hot wires and 7 neutral wires all coming out of a conduit pipe and you have no idea which hots go to which neutral.

If you think you need to, you just don't have the skillz yet. Work on that.

seharper said:

I'm glad whoever built your house saved $30 on that service panel... hope he loved those pizzas... but a full panel is an intolerable situation. Since total panel replacement isn't exactly DIY-friendly, I advise adding a subpanel. A stupidly, madly, huge subpanel. Spaces are cheap. I like to see houses have about 50 spaces between main and added sub. A space is what 2 slimlines fit in. You can go with GE if you really want to, but if you have any aspirations for generator in the future, a Siemens main-lug panel is a better choice.

You are right, AFCIs will never exist in double-stuff.

When you're in a hole, stop digging

I've done loads of reverse-engineering circuits from the panel side, in a much worse situation than yours. You do not need to access the receptacles at all. Imagine 11 hot wires and 7 neutral wires all coming out of a conduit pipe and you have no idea which hots go to which neutral.

If you think you need to, you just don't have the skillz yet. Work on that.

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I already have two subpanels. A total of three panels for the house. I am not sure about adding even more. That's a different project though and if I do that it will be hired out, that's beyond me.


As far as on the panel side, I do not see ANY clothed wiring. Nothing inside the panel suggested this wiring exists. The clothed wiring shows up in some receptacles and switch boxes only. That's why I said they have rewired before and either the electrician skipped some work and they didn't notice, or they were only paid to do some of it but not all. I am not sure how you would trace that from the panel side. Besides, I am fixing different things at each box anyways, at one box it could be changing an old style round dimmer to a decora dimmer, at another box it could be changing a receptacle to an unswitched one because I am not using a floor lamp, in another case it may be removing expansion foam inside a box because someone thought that's a good idea to keep bugs out, so finding this clothed wiring in some boxes is just another item on the list. Oh by the way, this wiring had been previously messed with, as I see layers of tape over these crumbling insulation already. I have to pull them out to see how bad they are. If they are really bad and not fixable right now, I'd rather turn off that circuit altogether.

TarheelTerp said:

Some... likely means they did what was needed and left the rest be.
Before you started poking at things... was there some problem?

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No, but then again, no one is there to experience a problem. We bought the house but haven't moved in yet, and won't now until this COVID-19 crisis is over. So the house is vacant. I am sort of moved into one room because I am spending a lot of time here now getting ready. My family is at the old house till it's sold, and looking unlikely it will be sold soon with the market the way it is.


Like I said I did a full inspection, and had all the panels looked at, everything has been rewired on the panel side, and checked the permits as well. So I had no clue that there may be some ancient wiring.


The first clue was while I was crawling on the underside to fix a cracked cast iron kitchen drain, on my way I went past some of these old wiring. There were two of those wires sitting on dirt under the crawlspace, uncapped, unterminated. I thought those were old abandoned wiring, didn't think much of it. Next time I was dragging in some PVC pipes and I remembered to bring in a voltage tester just to confirm...and to my amazement those wires were live. I put some wire nuts on them pushed them aside and went about my way to fix my drain issue. Then I need to make another trip down there to test for leaks after the repair was done, and this time I had a helper so I can tell what circuits these are on. I also terminated those wires into two metal boxes, and screwed the boxes onto the underside of the floor joists, then I turned those circuits off.


I went back to the main panel and the two subpanels and took the covers off and confirmed that I did not see any old clothed wiring in them. So they were spliced somewhere else.


At the same time I started to do little minor electrical stuff that I had planned to do anyways. This includes changing out some old receptacles purely for cosmetic reasons, like an ivory colored receptacle with white cover plate and both were painted over partially in blue, and the cover plate is cracked. I usually just change them all out to decora anyways.


Then one of the receptacles I opened the cover plate and found the entire receptacle encased in expansion foam. Someone had sprayed on the inside of the box with foam. Pretty sure this stuff is flammable so I started to either dig them out or take the entire box out to replace them. I found some of these wiring in foam. There is no way to not "disturb" this wire and to clean the foam off it. Once I started doing that, I wanted to find the other end of this wiring so I gradually opened more and more boxes. In two boxes even if I don't tease out the device and just use a flashlight to look in the back, I can see some exposed bare copper and that's not a ground conductor as those have no ground conductor. I had no choice but to remove the receptacle to see what's behind and try to rectify it if I could. I could tell someone already messed with it with tape covering some of the bare copper, and they used GFCI receptacles which takes up more room and I think when they pushed the GFCI back into the small handy box they messed up the wiring again.


Now I was able to replace three of these short wire already, one ran from the inside of an exterior wall to an outside security light, and another two were back to back receptacles in different rooms, short runs that I was able to easily replace by removing one box and feed the short piece through. As I said it's not just for this rewiring effort I am fixing other things as I go along the way anyways. What I am doing helps me get a good picture of what goes where, and any other rewire I might or might not do will be easier in the future once I mapped this out schematically.

I was able to remove two pieces of this wiring completely between two wall receptacle boxes about 4' apart horizontally. I know the part of the wiring inside the box is bad, brittle, crumbling, from all the twisting, folding, pulling and pushing over the years, but I wanted to have a look at the part of the wiring outside of the box to see if they are in the same bad shape or if they may still have some life left. In other words, if the wires outside of the boxes are as bad, then there is no fixing anything except to replace all, but if they are in much better shape then my option of either loosening the clamps inside the box to pull in more slack or to use heat shrink tubing on the crumbled ends may work to buy me some time.

Here are some pictures of this piece of wire. I already cut off the crumbled portion inside the box. The outside black colored sheathing seems to be OK, It survived the hard pull through the stud holes, but if I were bend it back and forth at a 90 degrees like 5 to 6 times it will break the sheathing.





I used a razor blade to cut open the sheathing, inside are two conductors wrapped in paper. This paper coiled around on the outside and it's brittle.



If I then tear the paper away I then see the cloth insulation. That seems to be in pretty good shape actually.



If I cut away the cloth insulation, there is some black brittle plastic coating on the conductor but they broke off easy too.



Thoughts? Do I have time to plan out the rewire in phases or is this a "the house would be on fire tomorrow" situation?

By the way, I have been reading up on this clothed wiring on the net and there is a bunch of warning about abestoes, that if I touched this I would release abestoes into the air and get lung cancer. I have already touched about a dozen boxes, where is the abestoes? Is it part of the outer sheath or the inner cloth? Is it the black tiny dust particles that came off when I exposed the various layers? Is it a significant risk?