Message Boards

I know every situation is different, but how expensive is this???????? TIA

I think this is a task for an electrician.

Yes, for sure, and costly. I just wondered if anyone here had experienced this...Thanks.

Pardon my ignorance...knob and tube?

I don't know either.

Froo, knob and tube is the type of wiring found in old houses like mine. Knob refers to porcelain knobs that the wiring is wrapped around and I guess the tube is the covering of the electric wires.

In the picture below there are some of the porcelain knobs from which I have hung the baskets.

I also am concerned because my house has this type of wiring which is supposed to be a fire hazard. We can't afford to replace it but I would be concerned with re-sale impact. However recently I spoke to a young neighbor who moved here not too long ago and they did replace it in their house, she said it would not be a detriment to a buyer who would want the house because of its age.

Our wiring has been update to a certain extent. We had circuit breakers installed (instead of fuse boxes which were the norm with K & T) and the wiring into the attic is totally new (grandkids sleep up there!) We do have insurance and that is supposed to be a problem in getting coverage till the old wiring is updated.

I guess the cost would depend on the extent of the rewiring and the size of the house. I'm not too sure how they do it without removing walls which would be a crime in a house like mine that has all original plaster walls. Guess it can be done by just threading the new wires through the walls. I remember as a child having to stick my arm up in a hole (cause it was smaller) to grab the wire my Dad was feeding down or up through the wall.

p.s. thanks for this thread. Think I'll ditch the hanging baskets that is such an old look!

This message has been edited. Last edited by: lady of shallot,

Knob & tube is not unsafe by itself because the hot and neutral wires are separated each having their own knob to attach to. As I understand it, the problem comes in as we try to update houses and therefore need more outlets, circuits, etc.
If you patch into knob and tube and cut into it with one "wire" with both the hot and neutral in it (like romex) the hot and neutral of the K&T come too close leaving a potential fire hazard.
So, to avoid this, people just replace it.
I'd post on the Handyman Wire. Lot's of great information over there.

Whew...glad the definition wasn't an obvious one. Live and learn.

Jaysmom gave a decent quick description of K&T wiring. Here is a more detailed one from wiki.

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

If you aren't doing a gut job on the house the expense will depend on access to either the top or the bottom of the wall. If it is a single story house with a basement or crawlspace below and an attic above running new Romex into the walls isn't that difficult. It is definitely something for a licensed electrician to do, in some areas a homeowner can do their own wiring but in some areas that isn't legal. In my town I can pull a permit to do wiring in my own house but not for pay in someone else's house without a license.

I haven't priced out rewiring a house, my dad (an industrial electrician) and I rewired their last house back in the 1980's, but we did a gut job on that turn of the century home. I trained as an electrician in high school but don't work in the trades. I suspect you're looking at $50 - $100 per device today, but I'm not sure. You'll also want to upgrade the service entrance to a larger system a 100 or 200 amp service depending on HVAC load and size of the house.

Thank you for the information. I posted here kind of in a panic to see if anyone had gone through this. DS is trying to buy his first house and the inspection brought this to light. Now the decision has be made as to how to respond to the seller as they have already lost one buyer and they are not willing to make "repairs". Both DS & I spoke to different electricians today who were really willing to give us the run down on what would need to be done. They both outlined the same plan and were close is their price guesstimate.

I knew that collectively there is a wealth of knowledge here, and that you all try to help, so I posted the question.

Thank you to all who replied.

Thanks, Sparky.

I have some personal experience with knob and tube wiring too. There was a lot of it in the 1870 Victorian we lived in for 10 years. In fact, there were 3 different types of wiring reflecting advances in years up to when we had the kitchen gutted and replaced.

We never had one bit of trouble with the electric in that house. The knob and tube worked as well as the copper new stuff. I don't know if we were just lucky or what but it was never an issue for us and it wasn't an issue for the poeple who bought the house. We've stayed in touch with them and 3 years later they still haven't had any electrical problems.

So, just being old doesn't necessairly mean bad.

quote:

I suspect you're looking at $50 - $100 per device today,

What does this mean, Sparky?

My Dog, I only got nervous about my wiring (which works fine) when a local real estate column said people can't get insurance on houses with knob and tube wiring. When I wrote him that we did have HO insurance he replied that that was only because we have lived in our house so long.

quote:

Originally posted by lady of shallot:

quote:

I suspect you're looking at $50 - $100 per device today,

What does this mean, Sparky?

My Dog, I only got nervous about my wiring (which works fine) when a local real estate column said people can't get insurance on houses with knob and tube wiring. When I wrote him that we did have HO insurance he replied that that was only because we have lived in our house so long.

Well, maybe things have changed in the past few years but we bought our house in 2001 and our insurance never even asked us about the wiring. We sold it in 2009 and the new owners have insurance so I don't know.

It may depend on the region where you live and state laws.

Back in the day when I was learning to be an electrician the going price was about $10 per device, a device being an outlet or a switch in new construction. Given 35 years of inflation and that we're talking retrofit $50-$100 is probably not unreasonable. That said, I haven't had to hire an electrician to do anything for me so I could be way off.

Knob and tube's design accounted for the lousy lifespan of the insulation of the day. It will continue to work fine for a very long time the copper doesn't breakdown. That said, houses wired with knob and tube were wired for a much simpler time, when a simple fan and a couple of lights were the typical load in a bedroom or living room and kitchen appliances were much smaller or non-existent. A modern home has much higher power demands for TV's, home theater, larger and more plentiful kitchen appliances and of course computers and their associated hardware. Service entrance size has increased over the years where a typical home has a 200 amp service today versus a 60 amp service in the 1940's and 1950's. Air conditioning was probably the largest driver of that and the increase in house size.