Knob & Tube Wiring? Replace!

LESLIE: Christine in Ohio, you’ve got The Money Pit. How can we help you today?

CHRISTINE: We have a 1930s home and the owner, he built it for himself and lived here for a while. The electricity has been replaced since then and it’s a new box with the on-and -off switches and a lot of labels, including one that says “gutter heater,” which I’m serious about.

TOM: OK.

CHRISTINE: But the question is we’re painting the whole house and all the outlet boxes are being replaced and the switches. And we’re replacing the switches but the wires look like they’re original to the home. Do those need replaced as well?

TOM: How old is the wiring? When was the home built?

CHRISTINE: 1930-ish.

TOM: Is it knob-and-tube wiring? Do you know what that is?

CHRISTINE: Well, I thought that meant what was in the box. So I guess I do not because the box in the basement is just the switches.

TOM: The panel may have been fuses and then upgraded to circuit breakers but what you’re concerned about is the wiring in the wall. I’ll say this, if it’s knob-and-tube wiring – which is the original form of central wiring that was added to homes around that time, by the way – that type of wiring has to be replaced because it’s not grounded and it’s not groundable. If it’s really any other type of wiring and as long as it’s wired correctly – and your electrician can check all that – then you could probably keep it.

CHRISTINE: OK.

TOM: But knob-and-tube wiring is easy to spot. It’s a black rubber coating. It is strung along the sides of wood beams from ceramic tubes. And whenever it goes through a beam – it’s strung from the side of beams with ceramic knobs. And whenever it goes through the beams, there’s a ceramic tube that goes through it. And that type of wiring is very unsafe.

So, other than that, I think as long as everything’s wired properly, you should be good to go. It’s not a do-it-yourself project, by the way. You need to have a professional electrician do this work for you, Christine, OK?

CHRISTINE: Is it possible that the wiring – because I didn’t see anything that looked like what you’re describing. But I don’t see how they could not have – how they could have replaced it if the wiring that I’m seeing – it looks like, you know, it’s just coming out of the light switch, say, under the box plate. It’s got a cloth covering all around it.

TOM: You should not be doing this work yourself, Christine. This is not a difficult thing to assess for a professional electrician. There are a lot of places, aside from inside those boxes, where you can see the type of wiring. Any exposed framing in the attic or basement, for example, you’ll see this wiring, OK?

CHRISTINE: Thank you so much.