Knob and tube!

[Nealcrenshaw]

Can someone inform me why does the wire wrap around the tube for insulation if the wires have insulation on them?
Why didn't they just run the wire without the tube?

[Torque1st]

http://en.wikipedia.org/wiki/Knob_and_tube_wiring

[nissan_crawler]

knob and tube lends itself to some of the scariest wiring practices I've ever seen in my life.

[dipper]

there should be no talk of knob and tube on a garage forum! lol.
it's bad enough in houses. At least if it's in a garage, you can probably rip it all out easy enough and start over with some romex.

[saywhat]

Unfortunately for me, I still have existing Knob and Tube in the attic along with other sketchy open splices from the previous owner, but it will be addressed this winter... Scary stuff...

[tfi racing]

Is it really that scary?You have to consider the house hasn't burnt down in seventy five years and chances are nobody got electrocuted in it either!An original, unmolested knob and tube system is a real work of art and believe it or not,craftmanship,the electricians way back when took a lot of pride in their work.The ceramic tubes and insulators are just that,to protect the wood from the heat generated by the conductors.
Having said that,if you have that old crap in your house,I recommend getting it replaced as soon as possible!You are now past the safe ampacity limit of that system and do risk setting your house on fire!It was only intended to provide a light bulb in each room and not all the electrical appliances and equipment we have today.Most insurance companies will not insure your home if it has knob and tube wiring,so start budgeting for replacement.

[nissan_crawler]

They key word is UNMOLESTED, which 99.8% of them are not. Most of have some scary homeowner splices on them.

[trainer]

Unmolested or not, i'd be re-wiring as soon as possible.
THe reason is that the wiring would be a minimum of 70 years old, and the insulation materials have probably deteriorated to some extent.
My house has the remains of some knob and tube wiring in the basement, and the insulation crumbles to the touch

[bomber]

AMEN -- the knob and tube in a previous house would shed it's insulaation if you looked at it sternly . . . . . .

while it's a kick to see, and would love to have it in my shop (looking like Edison's shop on Florida) I wouldn't want to have hot . . . .

[Torque1st]

A little knob and tube running to a clear light bulb in the shop running on about 90V with a fuse to protect it might be a real conversation piece. Along with the Tesla coil or Jacobs ladder in the corner and the old crank phone on the wall...

[saywhat]

A little knob and tube running to a clear light bulb in the shop running on about 90V with a fuse to protect it might be a real conversation piece. Along with the Tesla coil or Jacobs ladder in the corner and the old crank phone on the wall...

I will make sure to save some of the old knobs for you after the updated stuff goes in.

[kartracer23]

Unfortunately for me, I still have existing Knob and Tube in the attic along with other sketchy open splices from the previous owner, but it will be addressed this winter... Scary stuff...

I've got some of those, too. Spliced with lamp cord & speed nuts. :)

Basically, here's what a number of electricians have told me: the stuff in the walls is probably fine and not worth pulling out if it's hard to get to. Replace anything that's easy to pull (first floor up from the basement, attic down to 2nd floor, etc.). Replace everything in attic & basement.

I've had estimates everywhere from $2,500 to $6,000 to rewire. I'm also going through and putting in the old style push-button switches-have a few rooms of those done.

[Torque1st]

I will make sure to save some of the old knobs for you after the updated stuff goes in.
Thanks! If you do let me know what the shipping is. I promise the wire run will be out of reach. :)

I have a ceramic and Bakelite toggle switch. I have seen turn style and pushbutton switches also.

[krusty the clown]

my house was still using knob and tube when i bought it. it's now completely rewired. but i still have the old crank phone!

[dwilliams35]

It's really some pretty good stuff once you get down to it: lasts a long, long time; I'd trust it over some of the early romex. Biggest problem is just the simple fact, as has been touched on here already, that it was put in when there was one 100w lamp and a single wall plug in any bedroom, maybe two plugs in a kitchen, etc. etc.: it generally follows a wiring scheme that just simply can't handle a 2008 electrical load: most whole houses were on one or two circuits.

[Nealcrenshaw]

Wow!!! Good stuff!!!

[rburke65]

I used to rewire houses for a small electrical contractor for 11 years. It was 90% of all the business he did. Knob and tube wiring is really a very safe wiring system. The only place the hot and the neautral wires even come close to one another is inside the boxes themselves. True the insulation on the wiring would be crispy by the time we would get there to rewire but there was no shame in that! Usually this was the wiring in the basement exposed to all the dampness in the summers (dirt floors) and the extreme heat in the winters from the old coal furnaces. It was that wiring that we would replace. And if left alone it was fine, it was when the home owner would start splicing here and tapping into it over here and.......before you know it it becomes a real over loaded fire trap! But the original wiring and the code of the day was very safe.

[LoneGunman]

The insulation crumbling is scary but look how long it's lasted usually without problems. I've seen scarier romex wired houses by todays romex only electricians, the guys who claim to be an electrician but has only done new construction single family developements. I don't think I have ever ran across a PROPERLY done K&T splice that failed.

[nissan_crawler]

Yeah, but the thing is, everybody's talking about "unmolested" and "properly done" knob and tube. When is the last time you saw a system that followed that? All the knob and tube wiring I've seen has been scary as hell. Yes, that was due to what had been done to it, but still.

You're talking 70 years of idiots changing it god knows how many times. I have the early romex that's insulated (still fine) and has the cloth binding to hold the wires in a group (whatever it's called). I'm rewiring the house. Is the wire itself bad? No, but there's no grounds, and what has been DONE to the wiring is downright atrocious in places.

One breaker will run a bed room light, 2 of the 4 outlets in another bedroom, the dining room light, an outlet in the kitchen, two outlets in the den, and the garage door opener. :spit: Seriously, wtf? :headscrat

I found one circuit to have 96 volts on it while the others have 118. :wtf: Yeah, that breaker is off until the wiring is redone.

While the basic principle of knob and tube may not be bad, almost every existing installation of it is, from what I've seen.

[trainer]

I think one of the main issues with K&T wiring is that over the years, the people who knew what they were doing and tried to do things right have replaced it with romex rather than trying to add on and splice into it. They people who did the hacks know just enough about wiring to get in trouble. (ever hear the phrase A 'little' Knowledge can be dangerous"?)

Also, I dont think there's many electricians around who are trained on K&T and they wouldnt want the liability of doing anything to it rather than replacing it.

My house also has some early romex without a ground on one circuit. It would be hard to replace without opening up the ceiling. I've added a Ground fault breaker to it until I can get it done right.

[Blue]

I've got some of those, too. Spliced with lamp cord & speed nuts. :)

Basically, here's what a number of electricians have told me: the stuff in the walls is probably fine and not worth pulling out if it's hard to get to. Replace anything that's easy to pull (first floor up from the basement, attic down to 2nd floor, etc.). Replace everything in attic & basement.

I've had estimates everywhere from $2,500 to $6,000 to rewire. I'm also going through and putting in the old style push-button switches-have a few rooms of those done.

Those price quotes are good to know. I have a large, old house, and I think it probably has a mix of K&T, romex, and who knows what else. And I KNOW there is all sorts of amateur wiring that's been done (Thanks a lot, Dad! :) ). Also has an old fuse box (no breakers). Several outlest in the house have just "stopped working." My guess is that if the insurance man ever saw it, he'd probably drop us. we've been in the house so long (30 yrs), with no claims, that they probably haven't kept up with it.