knob and tube

[electricalperson]

a house im working at has white knob and tube. the house was built in 1900 and im wondering if this is wiring from 1900 as well? most 1930s knob and tube is black

 

[charlie]

. . . The house was built in 1900 and I'm wondering if this is wiring from 1900 as well? . .

I would bet against it since most homes built then had no electricity. Electrical wiring was normally added later as gas lights were replaced or the REA took effect for farmsteads. :smile:

 

[electricalperson]

I would bet against it since most homes built then had no electricity. Electrical wiring was normally added later as gas lights were replaced or the REA took effect for farmsteads. :smile:

i didnt find any old gas pipes anywhere. this house was built near the ocean in a town that has a pretty good history when it comes to whailing or fishing and its a pretty nice house. its possible it could ofbeen wired in 1910-1920. has white knob and tube and really thick black 14 gauge romex. the light fixtures have parts made by bryant. same with receptacles those are bryant or some company called tek

 

[al hildenbrand]

I've never run into K&T loom in any color other than the "bituminous" black. I have, upon rare occasion, found the conductor insulation to have a whitish outer coating. In the instances I found, the white was correctly used for the identified conductor, the energized conductors were the common bituminous black. My sense of the installations was that all of the white conductor insulation was of a more recent install than 1900, more likely around 1930.

I have a couple lengths of early 1930's NM 14/2 and 14/3. They are massive by comparison with modern thermoplastic NM. The copper gauge is the same, but that outer covering on the old stuff was really thick.

 

[Speedskater]

In my 1939 house, all the knobs and all the tubes are white.

 

[charlie]

In my 1939 house, all the knobs and all the tubes are white.

But the wire is not. I have never seen anything but black wire with K&T.

 

[iwire]

Maybe asbestos?

I really don't know that it is, just that any asbestos wire I have seen has been white.

 

[Speedskater]

But the wire is not. I have never seen anything but black wire with K&T.

One wire is white, one wire is black. At least in the rafters, in an outlet box the color may rub off.

 

[electricalperson]

ill try to get pictures of it. i found a group of 3 wires coming up and i dont know what they are since i stopped feeding it. i found a knob that has a brown glazed shiny finishes. all the knobs are glazed as well

 

[al hildenbrand]

i found a knob that has a brown glazed shiny finishes. all the knobs are glazed as well

Now that's a new one on me. Were they solid, the kind that the conductor is tied to or wrapped around; or were they the more common two piece that pinches the conductor?

 

[electricalperson]

Now that's a new one on me. Were they solid, the kind that the conductor is tied to or wrapped around; or were they the more common two piece that pinches the conductor?

solid the conductors are tied to it

 

[K8MHZ]

ill try to get pictures of it. i found a group of 3 wires coming up and i dont know what they are since i stopped feeding it. i found a knob that has a brown glazed shiny finishes. all the knobs are glazed as well

People collect K&T components in good condition. Don't throw them away, sell them on eBay.

The most common are the white ones. Glazed brown insulators are not as common and were probably the high end units of the time.

The conductors I see commonly used on K&T systems were marked white for the neutral conductor at one time but the coloring has long worn off, making it difficult to tell one conductor from the other.

I also suspect the wire diameter to be insufficient. I have never taken a micrometer to one of the old conductors but some of them sure look smaller than 14 AWG to me.

 

[LarryFine]

Most of the K&T houses I've experienced had it added after construction, and most were built gas-lit. The electricians would pry up two or three upstairs-hallway floorboards the length of the house and drill the joists with brace'n'bits.

They'd run this pathway very close to the front-to-back load-bearing interior wall, so they could fish horizontally into the room and hallway ceiling spaces for ceiling lights. Later, and in fancier houses, they'd drop switch loops down the wall.

You'd typically find such a house supplied by a 30a 120v service, with both conductors fused regardless of whether one was grounded. One 15a circuit would run the downstairs lighting, and the second in the attic for upstairs.

Receptacles were rarely installed in these first retro-wired houses, because nobody had electrical devices, because nobody had wiring, because . . . It had to start somehwere. Light was the biggest demand at first, then a fan, a toaster, etc.

The lights were pull-chain pendant sockets at first. One of the first home devices sold was the screw-in socket taps, sometimes with and sometimes without its own pullchain. These guys:

 

[electricalperson]

Most of the K&T houses I've experienced had it added after construction, and most were built gas-lit. The electricians would pry up two or three upstairs-hallway floorboards the length of the house and drill the joists with brace'n'bits.

They'd run this pathway very close to the front-to-back load-bearing interior wall, so they could fish horizontally into the room and hallway ceiling spaces for ceiling lights. Later, and in fancier houses, they'd drop switch loops down the wall.

You'd typically find such a house supplied by a 30a 120v service, with both conductors fused regardless of whether one was grounded. One 15a circuit would run the downstairs lighting, and the second in the attic for upstairs.

Receptacles were rarely installed in these first retro-wired houses, because nobody had electrical devices, because nobody had wiring, because . . . It had to start somehwere. Light was the biggest demand at first, then a fan, a toaster, etc.

The lights were pull-chain pendant sockets at first. One of the first home devices sold was the screw-in socket taps, sometimes with and sometimes without its own pullchain. These guys:

in the book i have it shows appliances that have an edison base screw shell so they could put it in a light socket and use whatever it was. i never seen one of these in real life yet

 

[iaov]

People collect K&T components in good condition. Don't throw them away, sell them on eBay.

The most common are the white ones. Glazed brown insulators are not as common and were probably the high end units of the time.

The conductors I see commonly used on K&T systems were marked white for the neutral conductor at one time but the coloring has long worn off, making it difficult to tell one conductor from the other.

I also suspect the wire diameter to be insufficient. I have never taken a micrometer to one of the old conductors but some of them sure look smaller than 14 AWG to me.

I've thrown away a ton of the stuff.

 

[al hildenbrand]

I've thrown away a ton of the stuff.

I almost don't have the heart to show you this link.

Used knobs $30.00 @.
Used tubes $35.00 @.

 

[al hildenbrand]

in the book i have it shows appliances that have an edison base screw shell so they could put it in a light socket and use whatever it was. i never seen one of these in real life yet

I have had the experience of working in a market with a lot of houses built in the 1905-1935 period that, when I upgraded them, were still nearly pristine, as-originally-wired. There would be two circuits, each 15 Amp 120 Volt, and the service disconnect was 30 Amp 120 Volt.

One circuit was originally only lighting, with maybe one receptacle outlet in the living room.

The other circuit went to a three gang wall case in the kitchen. The first gang had a single pole snap switch that controlled the pilot light in the second gang (a 4-7 Watt Xmas tree bulb behind an inch diameter lens) and the third gang which was an Edison screw shell. Sometimes there was a hinged cover on the screw shell and always there was a screw in adapter for a two wire receptacle.

 

[charlie]

My bedroom in my parents house had a single overhead hanging Edison base socket with a twist switch and an additional Edison socket at right angles and above the one that hung straight down. I assume the intent was to screw in an adapter for plugging something in if you needed to run an additional lamp or radio. The room had no other receptacles so the screw in adapter was used.

 

[480sparky]

..... and the third gang which was an Edison screw shell. ........

Like this?

 

[glene77is]

In my 1939 house, all the knobs and all the tubes are white.

Speed,
The OP may mean that only the LOOM was black.
Just for the sake of having stated it,
The Loom is the tubing, flexible, made of canvas and cambric and varnished.
The insulation on the soft drawn copper is usually old carbon black rubber.
Much of the K&T I've worked with has lost its insulation in the hot attics.

Speaking of old Romex, the stuff I've seen installed from the 40's, prior to the 50's TW insulation, had paper strips wrapped like a cork-screw around the rubber insulation. There are special techniques for working safely with this old stuff, as it will fall off in your hands!

Well, let's see where this thread goes. :smile: