65 volts on the ground wire

[e57]

I wrote a paper on the topic of K&T some time ago - some might find of interest - just don't re-post it on any handyman type sites...

 

[danickstr]

Nice comprehensive accounting of the "demon K&T"

 

[Power Tech]

Prove it!

Properly done and maintained it is just as safe as any other wiring method IMO. When manipulated by people with little understanding of the methods, and / or buried in insulation is when problems arise. Many of these issues are addressed in your code book.

Since many K&T installations were done in an era before circuit breakers - over-fusing was what resulted in fires - not the wiring method IMO.

I do have pictures of charred wood from K&T. They used to twist the wire around the main wire and solder. The solder connection breaks with age and you have a glowing connection. I have seen this on many homes. I can't believe you are standing up for wiring so old the insulation falls off.

 

[e57]

I do have pictures of charred wood from K&T. They used to twist the wire around the main wire and solder. The solder connection breaks with age and you have a glowing connection. I have seen this on many homes. I can't believe you are standing up for wiring so old the insulation falls off.

1. I would find it hard to beleive wood would "char" if not having insulation as a medium to carry heat to it - that said the building would be in flames long before that....
2. A properly made splice has more current carrying capacity that the wire itself -WITHOUT SOLDER. SOLDER IS ONLY A MEANS OF SEALING THE JOINT.
3. A properly made joint does not break down with age - only ones that were contaminated - or not made properly.
4. Depending on a lot of factors - the isulation will be just fine, or dry and brittle - 100 summers in a hot attic can do a lot to wire of all types - which is why you inspect it. If it is brittle, you ditch it... If you plan to insulate you ditch it...

Bottom line is making a blanket statement like 'K&T = FIRE' is just not true.... NM does not have a 100 year history - only time will tell how long it stands up. FYI - here there are many homes done in the 60's and 70's with TW, and/or THHN conductors in K&T. While the method is outdated, and labor consuming - it required a skill set that is quickly disappearing. I feel that many mechanics today would be better to know the skills - than not to - as there are some fundementals in the method that are lacking in todays electrician.

 

[LarryFine]

It's easy to criticize past technologies with the benefit of today's hindsight. If you're so smart, where were you when K&T was the modern thing being installed? (J/K)

It's similar to the discussions about why anyone would want a high-leg service, but forget that it originated as a modification to existing single-phase services.

Obviously, today we would opt for NM over K&T, but there was no NM when K&T was the accepted method of wiring. Even older factories used open wiring methods.

If K&T were deemed an absolute hazard, the NEC or local authorities would require that entire installations be scrapped and modernized. It's just not that dangerous.

 

[e57]

~Obviously, today we would opt for NM over K&T, but there was no NM when K&T was the accepted method of wiring. ~

If K&T were deemed an absolute hazard, the NEC or local authorities would require that entire installations be scrapped and modernized. It's just not that dangerous.

HERE- there is an entire era of NM that did not ever get installed because it was considered 'dangerous' by those making local codes at the time. Any cloth and cabric or two-wire NM cable is illegally installed as it was never allowed by code HERE at any time... K&T was the practice clear until the late 50's, early 60's so the only NM should be thermoplastic in TW - which I will say is also deteriorating with insulation break-down at a much faster rate than its cloth and cambric cousin for installs of that period.

And yes - no place in the NFPA 70 document known as the NEC - will it say if K&T is discovered it needs to be replaced. (Except for those found in 394.12 or by local code ammendment. Chiefly being 394.12(5)... And locally there is a waiver of that too...) Otherwise you can still extend or modify existing installations in the same methods if you desire. Although there are very few instances where one would need to - except for bringing the old conductors to a box to continue in a modern method.

 

[e57]

As far as insulation goes - See page 7 of 9

And or see if your area has something simular.

 

[Power Tech]

It's easy to criticize past technologies with the benefit of today's hindsight. If you're so smart, where were you when K&T was the modern thing being installed? (J/K)

It's similar to the discussions about why anyone would want a high-leg service, but forget that it originated as a modification to existing single-phase services.

Obviously, today we would opt for NM over K&T, but there was no NM when K&T was the accepted method of wiring. Even older factories used open wiring methods.

If K&T were deemed an absolute hazard, the NEC or local authorities would require that entire installations be scrapped and modernized. It's just not that dangerous.

I have seen some factories that still opt for the open wiring method.

View attachment 3665

This is where a K&T connection was. There was another upstairs in the wall that was really bad. I found another lighting splice in a farmhouse attic in another town. Another in a barn. I have the pictures, they are on another computer, from another camera. I have seen 4 different connections on the verge of pyrolysis.

In all honesty, I think it is a fire hazard. Every house I have and will ever do work at with K&T will get a warning letter. I warn them to change the batteries in the smoke detectors, and make sure they are in good working order.

If I tell them it is safe and it burns down tonight, I will have to have that on my conscience for my entire life.

There was a circuit breaker that blew and the owner asked me if it would last till the next day. I told him, it could last 20 years, or the entire gear could blow right now. I told him we needed to do an emergency shutdown immediately. He said l think I'll wait till tomorrow. It blew up in the middle of the night. It almost destroyed the gear. What if I would have said, ah, it'll hold. He called me and said he should have listened. It was a small repair at the time.

I'll get better at the pic's. How to make them bigger?

 

[George Stolz]

I'll get better at the pic's. How to make them bigger?

We click on them. It's intentional, to keep the page loading quicker and to keep the margins from being screwed up on your post. You did perfect.

 

[e57]

This is where a K&T connection was. There was another upstairs in the wall that was really bad. I found another lighting splice in a farmhouse attic in another town. Another in a barn. I have the pictures, they are on another computer, from another camera. I have seen 4 different connections on the verge of pyrolysis.

In all honesty, I think it is a fire hazard. Every house I have and will ever do work at with K&T will get a warning letter. I warn them to change the batteries in the smoke detectors, and make sure they are in good working order.

If I tell them it is safe and it burns down tonight, I will have to have that on my conscience for my entire life.

The picture is of seriously manipulated K&T tagged illegally and poorly at that - to NM with an abandoned conductor in the foreground. The dark spot you see was from the torch that was possibly used to solder the original wiring (which is no longer there...) - before that hack carpenter +/or plumber got to it. I see no example of K&T in an unmolested state...

FYI - what you are doing is being alarmist, and in some people's minds that can be considered fraud - YEP - "Fraud"....

 

[Power Tech]

The picture is of seriously manipulated K&T tagged illegally and poorly at that - to NM with an abandoned conductor in the foreground. The dark spot you see was from the torch that was possibly used to solder the original wiring (which is no longer there...) - before that hack carpenter +/or plumber got to it. I see no example of K&T in an unmolested state...

FYI - what you are doing is being alarmist, and in some people's minds that can be considered fraud - YEP - "Fraud"....

Oh, Cut it out.

 

[Power Tech]

The picture is of seriously manipulated K&T tagged illegally and poorly at that - to NM with an abandoned conductor in the foreground. The dark spot you see was from the torch that was possibly used to solder the original wiring (which is no longer there...) - before that hack carpenter +/or plumber got to it. I see no example of K&T in an unmolested state...

FYI - what you are doing is being alarmist, and in some people's minds that can be considered fraud - YEP - "Fraud"....

The work I was taking pictures of is handyman wiring spliced onto the K&T. I had the inspector taking pic's as well. Isn't our job to interpret what is safe. I am not trying to make work. Just pointing out what is unsafe.
Oh yeah, K&T is just as good as rigid conduit installation? Give me a break.
Aluminum romex is okay too ha. I mean, in a proper install for its time.

 

[e57]

Oh, Cut it out.

No - telling people their house will burn because there is K&T in it - as a blanket statement is patenly untrue... Pointing to torch marks from before it was even energized and calling it evidence of potential fire is a LIE...

The work I was taking pictures of is handyman wiring spliced onto the K&T. I had the inspector taking pic's as well. Isn't our job to interpret what is safe. I am not trying to make work. Just pointing out what is unsafe.
Oh yeah, K&T is just as good as rigid conduit installation? Give me a break.
Aluminum romex is okay too ha. I mean, in a proper install for its time.

Posting the pic (that one), and calling it "K&T" would be the same as is you posted the very same picture and said this is "cloth NM cable" which it also is - neither is an example of it being done right... IMO you are making a hard sell tactic at making work with fear as a weapon. "Sorry Maam' - gonna have to re-wire the whole house [sniff] Knob and tube... - I wouldn't spend another night here....." Sure hacks get at it - those who have no idea how to work with it should not.... And BTW - aluminum is gonna make a come-back - mark my words!!!

 

[Sierrasparky]

A blanket statement that NT is unsafe is not that bad a statement. I have rerely seen a NT installation that is not over loaded today. People replum their homes when the pipe clogs. Unfortunaltey they may not get the chance to re-wire when the tap connection fails because the home burned down already. It is ultimatley a decision that the home owner needs to consider.

 

[mivey]

A blanket statement that NT is unsafe is not that bad a statement. I have rerely seen a NT installation that is not over loaded today. People replum their homes when the pipe clogs. Unfortunaltey they may not get the chance to re-wire when the tap connection fails because the home burned down already. It is ultimatley a decision that the home owner needs to consider.

I would not make that blanket statement. K&T is a very sound wiring method if installed properly and not abused.

A good blanket statement for using scare tactics might be that K&T creates higher EMF than romex (I would not use it as a scare tactic).

 

[e57]

I would not make that blanket statement. K&T is a very sound wiring method if installed properly and not abused.

A good blanket statement for using scare tactics might be that K&T creates higher EMF than romex (I would not use it as a scare tactic).

Thank you - and go get your tin foil hat....

 

[Power Tech]

No - telling people their house will burn because there is K&T in it - as a blanket statement is patenly untrue... Pointing to torch marks from before it was even energized and calling it evidence of potential fire is a LIE...

Posting the pic (that one), and calling it "K&T" would be the same as is you posted the very same picture and said this is "cloth NM cable" which it also is - neither is an example of it being done right... IMO you are making a hard sell tactic at making work with fear as a weapon. "Sorry Maam' - gonna have to re-wire the whole house [sniff] Knob and tube... - I wouldn't spend another night here....." Sure hacks get at it - those who have no idea how to work with it should not.... And BTW - aluminum is gonna make a come-back - mark my words!!!

If Al romex makes a come back. I will not use it. Just like we did not use it in the 80's.

I wouldn't doubt you would use, just to prove a point. You probably smoke and leave the engine on when you fill up.

Did you even read the paper you posted? K&T was outlawed because of """FIRE""",,,,YEP,,,"""FIRE""".

And enough with your Harlequin Romance Crime Scene Investigation Fantasy. Don't give up the day job.

What is it with you? You are defending old, delapited wiring like it was your wife.

What did you do to have so much ego invested in K&T.

My personal opinion is it is a fire hazard. It almost electrocuted a friend of mine in the attic. I have seen and touched wire that the solder twist was loose and spinning. Discolored from heat with a charr mark on the wood. You call that a lie?

I think twice before calling someone a lire and a fraud.

This is a contractor forum. Not an apprentice forum. What are you a 2nd year apprentice?

 

[Power Tech]

1. I would find it hard to beleive wood would "char" if not having insulation as a medium to carry heat to it - that said the building would be in flames long before that....
2. A properly made splice has more current carrying capacity that the wire itself -WITHOUT SOLDER. SOLDER IS ONLY A MEANS OF SEALING THE JOINT.
3. A properly made joint does not break down with age - only ones that were contaminated - or not made properly.
4. Depending on a lot of factors - the isulation will be just fine, or dry and brittle - 100 summers in a hot attic can do a lot to wire of all types - which is why you inspect it. If it is brittle, you ditch it... If you plan to insulate you ditch it...

Bottom line is making a blanket statement like 'K&T = FIRE' is just not true.... NM does not have a 100 year history - only time will tell how long it stands up. FYI - here there are many homes done in the 60's and 70's with TW, and/or THHN conductors in K&T. While the method is outdated, and labor consuming - it required a skill set that is quickly disappearing. I feel that many mechanics today would be better to know the skills - than not to - as there are some fundementals in the method that are lacking in todays electrician.

If you found a splice behind a wall, with no box, would you call it safe?

Would you make a splice in a wall without a box and call it good?

Isn't that what K&T is?

I will tell the customer and you - That is how fires start. Do I really need to go through the theory of why we need a box?

 

[hardworkingstiff]

If you found a splice behind a wall, with no box, would you call it safe?

Would you make a splice in a wall without a box and call it good?

Isn't that what K&T is?

These are indeed good points.

 

[360Youth]

Wow, I gotta stop jumping to the ends of these treads without reading the earlier posts first. And now we return you to our regularly scheduled program..."As the Insulated Screwdriver Turns."