Knob & Tube Questions

[Little Bill]

I have an old home I'm working on. The power has been off for over a year and the POCO requires an inspection before they will re-energize. The old fuse panel was in such a mess I talked the new owner into letting me change it out to a breaker panel.

However, a lot of the wiring is still knob & tube and I haven't had to deal much with that stuff and don't know for sure what was ever legal or what the inspector is going to require corrected.

In these pictures you will see open splices, lights with no boxes, and boxes with no connectors. Was any of these scenarios ever legal during the time this wiring method was used?

 

[GoldDigger]

Open splices, usually soldered and then taped, were the preferred method of connecting K&T wire runs. Sometimes with a knob close for support, sometimes not. But what you have in the first picture appears to be a later tap of the K&T using the predecessor of NM. That connection should probably be made in a bo

The shiny boxes, open or otherwise, are later additions and are probably illegal if concealed and should be covered if not concealed (all as of the time they were installed.)

I am not sure what all of the options were for lighting fixture connections, or what type of bushing or connector is needed when entering a box with K&T wire.
Those light bulb sockets appear to be "temporary" using sockets designed for festoon lighting or construction of luminaires and need to be supported. Also the junctions have to be in boxes.

Whether the inspector requires all of these to be corrected before signing off is probably a local variation. My guess is most or all will have to be remediated, since the integrity of the original K&T has been disturbed. It may be easiest to abandon the whole thing and pull new home runs.

 

[mjf]

Yikes!!

I live in an older part of our country and I have had the "privilege" of seeing active and abandoned K+T on many occasions. I have seen the soldered and taped splices many times.

As far as the lights with no box....the wiring landed directly onto screw terminals of a porcelain socket holder (no box). I assume it would require a box nowadays.

They do make specific bushings for K+T to be landed into boxes.

I can't comment on whether or not any of it was ever legal, it's way before my time (except I know the K+T into "present day" boxes with no bushing is illegal).

 

[RLyons]

Our local city AHJ would have us remove all exposed K&T. Once a wire enters the structure a metal JB would be placed with rubber grommet to protect the K&T and circuit would be re-fed or fed thru exposed point to exposed point. Seems like a big waste of time to me as I'm more worried about the K&T in the now insulated wall than what I can see.

 

[Little Bill]

I've decided rather than ask the inspector a lot of questions, I'm just going to let him inspect what is there and let him tell me what he wants corrected.
I think the new panel will satisfy him as far as that's concerned because I've definetely
made it safer.

I'm doing away with some obvious wiring violations such as NM open spliced to power strips, ceiling fans with open splices, etc. Just don't want to fix a bunch of stuff that he might let slide. Reason being, the new owner said she was going to do a remodel soon but just needs the power on for now for insurance purposes.

 

[Little Bill]

Open splices, usually soldered and then taped, were the preferred method of connecting K&T wire runs. Sometimes with a knob close for support, sometimes not. But what you have in the first picture appears to be a later tap of the K&T using the predecessor of NM. That connection should probably be made in a bo

The shiny boxes, open or otherwise, are later additions and are probably illegal if concealed and should be covered if not concealed (all as of the time they were installed.)

I am not sure what all of the options were for lighting fixture connections, or what type of bushing or connector is needed when entering a box with K&T wire.
Those light bulb sockets appear to be "temporary" using sockets designed for festoon lighting or construction of luminaires and need to be supported. Also the junctions have to be in boxes.

Whether the inspector requires all of these to be corrected before signing off is probably a local variation. My guess is most or all will have to be remediated, since the integrity of the original K&T has been disturbed. It may be easiest to abandon the whole thing and pull new home runs.

I asked about the lights because some appeared to be original. I didn't post pictures of them. But the ones you mentioned as "temporary" probably are as I can see an outline on the ceiling where a light fixture was mounted. Someone told me a lot of stuff in this house was old vintage things, lights included. Since the original owners passed away, the house has been owned by at least two other owners. The last having lost the house in a repo. So no telling what was taken/sold from the original things.

 

[LEO2854]

I asked about the lights because some appeared to be original. I didn't post pictures of them. But the ones you mentioned as "temporary" probably are as I can see an outline on the ceiling where a light fixture was mounted. Someone told me a lot of stuff in this house was old vintage things, lights included. Since the original owners passed away, the house has been owned by at least two other owners. The last having lost the house in a repo. So no telling what was taken/sold from the original things.

Hey CUZ

Did you try to sell a rewire ?

 

[Little Bill]

Hey CUZ

Did you try to sell a rewire ?

Maybe for later. The owner just wants to get power on for now, but she plans on a remodel in the near future.

 

[LEO2854]

Maybe for later. The owner just wants to get power on for now, but she plans on a remodel in the near future.

That old BX cable is scary stuff and it's not grounded to the service, I've seen that stuff glowing in a few houses I've been in...

 

[PetrosA]

It kind of looks like a kit house to me, like an old Craftsman home (those floor joists couldn't get any farther apart ). The original wiring looks low budget, and the added-on stuff even worse. Let the inspector call stuff out and go from there. This place needs to be rewired. Just don't let her blow insulation in or anything in the meantime.

 

[Little Bill]

That old BX cable is scary stuff and it's not grounded to the service, I've seen that stuff glowing in a few houses I've been in...

Actually, I don't think it's BX, well at least the piece I checked. Some of it may be but what the piece I checked was just "Greenfield". Looks like they just sleeved some of it with the flex.

Now to be honest, the picture with what looks like BX might be because I didn't check it. But I took a piece down that went to some unused lights and it was just flex.

 

[LEO2854]

Actually, I don't think it's BX, well at least the piece I checked. Some of it may be but what the piece I checked was just "Greenfield". Looks like they just sleeved some of it with the flex.

Now to be honest, the picture with what looks like BX might be because I didn't check it. But I took a piece down that went to some unused lights and it was just flex.

Keep in mind before the 1950's BX did not have a bonding strip, and those guys used it as a sleeve through floors and that stuff ended up terminated at receptacle, and lighting boxes.

 

[david]

I've decided rather than ask the inspector a lot of questions, I'm just going to let him inspect what is there and let him tell me what he wants corrected.
I think the new panel will satisfy him as far as that's concerned because I've definetely
made it safer.

I'm doing away with some obvious wiring violations such as NM open spliced to power strips, ceiling fans with open splices, etc. Just don't want to fix a bunch of stuff that he might let slide. Reason being, the new owner said she was going to do a remodel soon but just needs the power on for now for insurance purposes.

in this area a re-meter inspection is a service only inspection. Do your inspectors inspect the branch circuits, here we do not for this type of inspection.

 

[K8MHZ]

in this area a re-meter inspection is a service only inspection. Do your inspectors inspect the branch circuits, here we do not for this type of inspection.

They don't in my parts (Western Michigan) but can take action against installations that pose an imminent safety hazard to the structure or occupants.

Our area has K&T everywhere. Right in my back yard. Literally, my detached garage has K&T wiring. Seeing it is very commonplace. There is even a hardware store up in the sticks that sells porcelain tubes. NOS.

Lowe's even sells surface mount light sockets that have both conductor screws exposed and un-insulated to hook K&T conductors to. I bought one just to prove they do.

 

[K8MHZ]

Splices with no box is still legal for knob and tube wiring. Take a close read of 300.15

 

[GoldDigger]

Splices with no box is still legal for knob and tube wiring. Take a close read of 300.15

I do not read it quite that way:
Where the only wiring method is K&T, splices can be in the open. This was done during the original installation.
But in most of the pictures, the K&T is spliced to a different wiring method.

Where the wiring method is conduit, tubing, Type AC cable, Type MC cable, Type MI cable, nonmetallic-sheathed cable, or other cables, a box or conduit body shall be installed at each conductor splice point, outlet point, switch point, junction point, termination point, or pull point, unless otherwise permitted in 300.15(A) through (L)

I do not see A-L applying to any of the splices pictured.

 

[Little Bill]

in this area a re-meter inspection is a service only inspection. Do your inspectors inspect the branch circuits, here we do not for this type of inspection.

There is only one POCO in the area that requires a re-connect inspection, and that is only for buildings that have not had service for one year or more, all the rest do not. This is the first time I have encountered it. In fact, the POCO has just put it in their bi-laws. They pretty much said the details of the inspection was up to the inspector.

I called him and he said he has to inspect the entire dwelling but would not require anything that was legal when installed to be brought up to current codes. He said he looks at the service (especially a fused panel) for correct OCPD, receptacles with grounding pins to have 3 wires, all rooms with lighting outlets have to have lights installed, anything unsafe.

 

[al hildenbrand]

Splices with no box is still legal for knob and tube wiring. Take a close read of 300.15

I agree, but I think you meant to type 300.16

I do not read it quite that way:
Where the only wiring method is K&T, splices can be in the open. This was done during the original installation.
But in most of the pictures, the K&T is spliced to a different wiring method.

The original wiring method first to electrify a structure, when installed in the first half of the Twentieth Century, commonly had additions added over time for receptacle outlets, wall switches and, occasionally, lighting outlets. Rather than fish K&T, installers turned to either early nonmetallic sheathed cable or armored cable as these products were available.

Today's 2011 NEC 300.16 does not retroactively apply to historic installations. One of the historic Code described practices was to install fished BX extensions where the armor was allowed not to be bonded to any EGC. Remember, most original K&T receptacle outlets and wall switches were, and are, in un-bonded steel wall cases.

The take-away from the 2011 NEC 300.16 and related passages is that it is STILL a Code approved practice to take the conductors in a cable or a raceway beyond a "terminal fitting" into open air in order to reach and be spliced to K&T wiring.

In the pictures showing friction tape at the end of the cable sheath, one must have knowledge of the local historical AHJ enforcement before one can make a blanket statement about the need for boxes.

 

[mgookin]

There is only one POCO in the area that requires a re-connect inspection, and that is only for buildings that have not had service for one year or more, all the rest do not. This is the first time I have encountered it. In fact, the POCO has just put it in their bi-laws. They pretty much said the details of the inspection was up to the inspector.

I called him and he said he has to inspect the entire dwelling but would not require anything that was legal when installed to be brought up to current codes. He said he looks at the service (especially a fused panel) for correct OCPD, receptacles with grounding pins to have 3 wires, all rooms with lighting outlets have to have lights installed, anything unsafe.

No smokes?

 

[Little Bill]

No smokes?

Well maybe a cigar!:lol:

I forgot to mention that. Here, anytime power is pulled and an inspection is required, we have to install smokes. Battery operated is fine for this.