I have a customer with a house that is completely wired in knob-and-tube and they would like me to rewire the entire house, but it is not possible. The question is, would it give reasonable protection to install a new panel with AFCI breakers and GFI outlets on the circuits that need grounded outlets installed?
Knob-and-tube
- Thread starter sllazar
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jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Knob-and-tube
Every thing is possible.If they want it do it.A patch man for a half day can fix anything you will do
Every thing is possible.If they want it do it.A patch man for a half day can fix anything you will do
Re: Knob-and-tube
There is a limit to using GFCI receptacles in outlets throughout an old house. Early K & T outlet boxes are too small (metal with a tight fill) to accept a GFCI device body. In some cases, branch circuit neutrals have been crossed-over and circuit polarity reversed.
Sure it can be done but it's not as simple as installing an AFCI panel breaker in a new box. Depending on the existing old house framing configuration, there are rewiring methods using wire pulling techniques and a good wall finish sub that can make it happen. It does take more than Bob Villa.
rbj, Seattle
There is a limit to using GFCI receptacles in outlets throughout an old house. Early K & T outlet boxes are too small (metal with a tight fill) to accept a GFCI device body. In some cases, branch circuit neutrals have been crossed-over and circuit polarity reversed.
Sure it can be done but it's not as simple as installing an AFCI panel breaker in a new box. Depending on the existing old house framing configuration, there are rewiring methods using wire pulling techniques and a good wall finish sub that can make it happen. It does take more than Bob Villa.
rbj, Seattle
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Knob-and-tube
And also watch out for 3-ways as many K&T use a wiring method that some of us call a Chicago 3-way which the travelers are the hot and neutral and the commons from each 3-way go to the light. which is a violation of todays NEC because it switch's the neutral and also puts the hot to the shell of the light after each other change of the switch positions.
I would try to replace as much of this wiring as possible. But then I do have the equipment to do this and I'm on a apartment job right now that the insurance company is requiring the owners to replace all the wiring before they can get insured,( owners wired it themselves). It's a hard job but can be done. 3 days on the first apartment and it was the easiest so far. but the job went for 17,000 so it is good money. Long drill bit's and a lot of know how is required. looking for paths to get from point A to point B can be fun.
[ November 11, 2004, 08:26 PM: Message edited by: hurk27 ]
Problem in knob&tube you will have many circuits that will be connected to the same neutral and AFCI's or GFCI's will detect this as a ground fault. GFCI receptacles will work for the ungrounded receptacles but as for AFCI's you will still have to track down which circuits are using which neutrals and separate them.
And also watch out for 3-ways as many K&T use a wiring method that some of us call a Chicago 3-way which the travelers are the hot and neutral and the commons from each 3-way go to the light. which is a violation of todays NEC because it switch's the neutral and also puts the hot to the shell of the light after each other change of the switch positions.
I would try to replace as much of this wiring as possible. But then I do have the equipment to do this and I'm on a apartment job right now that the insurance company is requiring the owners to replace all the wiring before they can get insured,( owners wired it themselves). It's a hard job but can be done. 3 days on the first apartment and it was the easiest so far. but the job went for 17,000 so it is good money. Long drill bit's and a lot of know how is required. looking for paths to get from point A to point B can be fun.
[ November 11, 2004, 08:26 PM: Message edited by: hurk27 ]
Re: Knob-and-tube
I have done a lot of house k and t reworks. With today's power demand, appliances, computers etc. I always update the receptacles, cut in replaster, drill etc. When the job is really difficult to rework I will some times leave the lighting alone. The lighting, hall lights, some bedroom lights do not draw that much power where it puts a high demand on the old wiring. Check with the local insp. they may agree.
Hank
I have done a lot of house k and t reworks. With today's power demand, appliances, computers etc. I always update the receptacles, cut in replaster, drill etc. When the job is really difficult to rework I will some times leave the lighting alone. The lighting, hall lights, some bedroom lights do not draw that much power where it puts a high demand on the old wiring. Check with the local insp. they may agree.
Hank
tonyi
Senior Member
Re: Knob-and-tube
If its two story, putting a panel on the 2nd floor and organizing all the 2nd floor stuff as verticle drops through the walls will reduce a lot of fish/pull hassle...
A Greenlee VersiBit and that aiming tool they have for it can accomplish miracles sometimes...
If its two story, putting a panel on the 2nd floor and organizing all the 2nd floor stuff as verticle drops through the walls will reduce a lot of fish/pull hassle...
A Greenlee VersiBit and that aiming tool they have for it can accomplish miracles sometimes...
Re: Knob-and-tube
I use those greenlee bits as well but I have been having pretty good luck with a sharp paddle bit and those quick release extensions.
Funny how your customer wants the house rewired and you dont want to do it. I am always telling my customers they need a rewire and they wont spend the cash.
I use those greenlee bits as well but I have been having pretty good luck with a sharp paddle bit and those quick release extensions.
Funny how your customer wants the house rewired and you dont want to do it. I am always telling my customers they need a rewire and they wont spend the cash.
Re: Knob-and-tube
I am very familiar with rewiring old K&T houses we do about 10 a year. I know that anything can be done for a price. This house is 2 story, has no attic, some walls are block and the basement is finished. This means holes everywhere with lots of plaster work, and thought that there might be a smarter way to make this house safe. Thank you for the thoughts on the shared neutrals, did not cross my mind. I am not in the practice of just blowing peoples money just because they have an idea of rewiring a house. I prefer smarter, more efficient, and value for the money spent. ROI
I am very familiar with rewiring old K&T houses we do about 10 a year. I know that anything can be done for a price. This house is 2 story, has no attic, some walls are block and the basement is finished. This means holes everywhere with lots of plaster work, and thought that there might be a smarter way to make this house safe. Thank you for the thoughts on the shared neutrals, did not cross my mind. I am not in the practice of just blowing peoples money just because they have an idea of rewiring a house. I prefer smarter, more efficient, and value for the money spent. ROI
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Knob-and-tube
And the latter part (Be safe) is hard to know without some very close checking of the connections and condition of the wires. if you can get to them.
I'm in the process of looking for a good IR camera to do behind the wall inspecting to look for splices and over loaded circuits. Hard to do in hot weather unless the house has air but in the winter with the heat set at a lower temp, a loaded circuit is very easy to trace through the walls and hot spots can be spotted. Also a good way to trace circuit path's as to see if the neutrals are running with the circuit or are wired to another circuit. It can't see through conduit but if there is a hot spot in a splice made inside of a conduit it will cause the conduit to heat up and this will show up. And there are many many other preventive maintains trouble shooting tricks that can be done with one.
The house (apartment's) I'm working on now has a flat roof and the crawl space is not accessible. So I'm unzipping the vinyl siding to make runs through the outside walls and to run across rooms to the light or inside walls. I have a zipper tool to close it back up. It's another path that we can use sometimes to get where we need to be. So far I have been able to drill a wall through the studs to about 14' from the outside to feed plugs and light switch's then fish up the wall to the roof joist to fish back to a light. I have the Greenlee Versa-Bits But the one small 5/8" one won't hold it's sharpness very long and is very hard to resharpen so I now use the extention's (I have 6-5') but just use a paddle bit in them for the smaller holes and It works fine. Those Kelms grips that come with the kit can be damaged easily too but are too valuable to change as they allow the wire to pass through the holes without catching on the studs. Also I found a Badminton Bird with a setscrew collar behind it will keep the drill point from hitting the drywall. Just shove the shaft of the drill through the rubber tip of the bird and cut the feather in about 3 places to allow it to collapse when it passes through the holes then cut it off before you pull the new wire in. Finding a supply of these is the next trick. But I found a bargain store here that sells replacement birds a 4 for two bucks. Cheeper than repairing drywall.
Ok I'm done boring you guy's.
My thoughts too as the reason of my signature: "Be fair Be safe Just don't be fairly safe".
And the latter part (Be safe) is hard to know without some very close checking of the connections and condition of the wires. if you can get to them.
I'm in the process of looking for a good IR camera to do behind the wall inspecting to look for splices and over loaded circuits. Hard to do in hot weather unless the house has air but in the winter with the heat set at a lower temp, a loaded circuit is very easy to trace through the walls and hot spots can be spotted. Also a good way to trace circuit path's as to see if the neutrals are running with the circuit or are wired to another circuit. It can't see through conduit but if there is a hot spot in a splice made inside of a conduit it will cause the conduit to heat up and this will show up. And there are many many other preventive maintains trouble shooting tricks that can be done with one.
The house (apartment's) I'm working on now has a flat roof and the crawl space is not accessible. So I'm unzipping the vinyl siding to make runs through the outside walls and to run across rooms to the light or inside walls. I have a zipper tool to close it back up. It's another path that we can use sometimes to get where we need to be. So far I have been able to drill a wall through the studs to about 14' from the outside to feed plugs and light switch's then fish up the wall to the roof joist to fish back to a light. I have the Greenlee Versa-Bits But the one small 5/8" one won't hold it's sharpness very long and is very hard to resharpen so I now use the extention's (I have 6-5') but just use a paddle bit in them for the smaller holes and It works fine. Those Kelms grips that come with the kit can be damaged easily too but are too valuable to change as they allow the wire to pass through the holes without catching on the studs. Also I found a Badminton Bird with a setscrew collar behind it will keep the drill point from hitting the drywall. Just shove the shaft of the drill through the rubber tip of the bird and cut the feather in about 3 places to allow it to collapse when it passes through the holes then cut it off before you pull the new wire in. Finding a supply of these is the next trick. But I found a bargain store here that sells replacement birds a 4 for two bucks. Cheeper than repairing drywall.
Ok I'm done boring you guy's.
physis
Senior Member
Re: Knob-and-tube
I think the single most important consideration is a "good" dry wall man. The way I look at it, it probably costs 3 or 4 times more for the electrician to save some sheet rock as it does for a good dry wall guy to put it back together. I do a lot of work where I prefer to save the wall and I can get it with the wall intact almost every time. But that drives the cost up.
If they're asking you to replace all the K&T they probably have an idea of what that means. Just make them aware of the damage you propose before hand.
I don't really have a problem with knob and tube, but would the gfi's and afi's be protecting them from the knob and tube if it weren't replaced?
I think the single most important consideration is a "good" dry wall man. The way I look at it, it probably costs 3 or 4 times more for the electrician to save some sheet rock as it does for a good dry wall guy to put it back together. I do a lot of work where I prefer to save the wall and I can get it with the wall intact almost every time. But that drives the cost up.
If they're asking you to replace all the K&T they probably have an idea of what that means. Just make them aware of the damage you propose before hand.
I don't really have a problem with knob and tube, but would the gfi's and afi's be protecting them from the knob and tube if it weren't replaced?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Knob-and-tube
Sam The one I'm on, the renters are still living there. Fun Huh!
Oh I also forgot to mention that the original panels were 3-R located at the meter packs owner had me move them into each apartment. The one I just did had only one 20 amp single pole breaker for the whole apartment. the others have some circuits fed from the wrong panels. or circuits that run through other apartments that are accessible to the tenants.
[ November 12, 2004, 01:25 AM: Message edited by: hurk27 ]
Sam The one I'm on, the renters are still living there. Fun Huh!
Oh I also forgot to mention that the original panels were 3-R located at the meter packs owner had me move them into each apartment. The one I just did had only one 20 amp single pole breaker for the whole apartment. the others have some circuits fed from the wrong panels. or circuits that run through other apartments that are accessible to the tenants.
[ November 12, 2004, 01:25 AM: Message edited by: hurk27 ]
physis
Senior Member
Re: Knob-and-tube
A lot of what I do is occupied residences.
I enjoy unoccupied, and a real super treat is new construction but the closest I usually get is stud wall remodels. I gotta get into commercial or industrial, this kind of work is really loosing it's appeal for me.
Edit: Wayne, did you say renters? Piece a cake, I always have owners.
[ November 12, 2004, 02:28 AM: Message edited by: physis ]
A lot of what I do is occupied residences.
I enjoy unoccupied, and a real super treat is new construction but the closest I usually get is stud wall remodels. I gotta get into commercial or industrial, this kind of work is really loosing it's appeal for me.
Edit: Wayne, did you say renters? Piece a cake, I always have owners.
[ November 12, 2004, 02:28 AM: Message edited by: physis ]
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Knob-and-tube
I go in with the idea that on a good day with a helper i will maybe get 8 items repulled.If any will take much more than 1 hour then make the holes.Patch men are good at there job so let them make a few $$$$ too.Your not doing the owner a favor if you spend 4 hours to keep from hiring a patchman.
I go in with the idea that on a good day with a helper i will maybe get 8 items repulled.If any will take much more than 1 hour then make the holes.Patch men are good at there job so let them make a few $$$$ too.Your not doing the owner a favor if you spend 4 hours to keep from hiring a patchman.
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