Had a chat with an old timer about knob and tube wiring

I was on a job last week in an 1890s house and the homeowner wanted to rip out all the old knob and tube. I told him it's a fire hazard, standard advice. But then his 80 year old uncle showed up, retired electrician, and said knob and tube is fine if the insulation isn't cracked and it's not overloaded. He ran it for 50 years without a problem. Now I'm second guessing how quick I am to condemn it. Anyone else had an old timer change your mind on something?

3 comments

3 Comments

green.noah27d ago

The uncle said insulation condition and load are the big factors. So how do you actually check that insulation in an older house without disturbing it too much? I've seen stuff that looks fine on the surface but crumbles as soon as you touch it. Your mileage may vary of course, but I think that's the real question here.

matthew37127d ago

Had a buddy who poked his head into an attic space and thought everything looked fine. He was in decent shape too, not much dust or critter droppings. Then he brushed against a section and his arm went right through the paper facing into a pile of what used to be insulation. Looked like gray crumbs mixed with mouse nests. That stuff was holding the house up by sheer habit. He ended up having to suit up and just start pulling out handfuls until he could see the ceiling joists. Took him two weekends and a lot of bad words.

fiona_hunt7127d ago

My buddy Tom found that out the hard way in a 1920s house he was helping flip. He was checking a run of knob and tube in the basement ceiling, looked solid from below, no cracks or anything. Then he went up in the attic to trace it and found a section near the chimney where the insulation was basically charcoal dust from years of heat cycling. A hot wire with no insulation left, just wrapped in old cloth that crumbled when he touched it. He said the rest of it was fine but that one spot would have started a fire for sure if someone had stuffed blown insulation over it. So I get what the uncle was saying, but checking every inch of that stuff is a lot harder than it sounds.