Knob and Tube covered by cellulose insulation

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Topic by srzsrz posted 06-26-2013 11:17 PM 57936 views 0 times favorited 3 replies Add to Favorites Watch
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6 posts in 2241 days

06-26-2013 11:17 PM

Topic tags/keywords: knob and tube cellulose insulation attic

The other day I went up into my attic the first time and discovered a nice surprise: Knob and Tube wiring covered in cellulose blown-in insulation. From what I understand, California is the one place where that is not per se illegal; in other places you’re supposed to keep the insulation away from the K&T. In California, they’ll let you do it if you have the wiring inspected first.

Given the numerous code violations in the wiring in other places, I am almost certain no such thing ever happened. My having a look at the one K&T to Romex splice that happens not to be covered in cellulose seems to have been enough that the lights powered by that splice are no longer working! Needless to say, the splice was not up to code. I’m pretty sure there are plenty more such splices hidden underneath the cellulose.

I’m considering having the insulation taken out. I’m asthmatic so there’s no way I’m doing this myself. The local insulation contractor I called, however, says they don’t normally want to do this kind of work when there’s K&T wiring, because they are afraid they’ll damage it. They’re going to call me back, but this has me thinking: what’s more dangerous, removing the insulation or not removing it?

By the way, as far as the actual insulating value of the insulation goes: it’s a very thin layer, piled up in some places and completely absent in others, and I doubt it does much of anything at all.

View Dan Lyke's profile

Dan Lyke

331 posts in 4120 days

06-27-2013 07:25 PM

Over Christmas break, my wife and I replaced the knob & tube wiring in our house with Romex. The K&T was just for the lighting circuits in the attic (and had cellulose blown in over it). We had to put a few holes in walls where we couldn’t fish the wires down, but it was doable: Usually we could take off a switch, tie a string to both wires, and we were able to pull one of those wires without breaking it… And use the string to pull back down the Romex.

So a possibility: plan on replacing the knob & tube, and tell your contractor that that’s what you’re going to do?

Also, save the ceramic when you pull it out: There’s a market for used K&T fittings.

-- Dan Lyke, Petaluma California, http://www.flutterby.net/

View J's profile


70 posts in 2556 days

07-04-2013 06:10 AM

There are blow-in insulation removal machines; they are essentially an oversized vacuum with a 6” pick up line. With miniml care (a properly equipped) insulation contractor should be able to remove the insulation without damaging the wiring, more specifically the insulation. The machines are designed to move volume, not pull a vacuum so strong it could pull a golf ball through a garden hose. In other words, unless there is some notable information you left out, removing the insulation using reasonable care will not result in damage to the wires. I would recommend calling other contractors until you find one that has the right machine and willing attitude/experience to do what you want. I’m not going to speculate on the current condition of your wiring, only that there is one way to know for certain. I wonder if this is a tactic by the insulation company you called to drive up the price, or if they just dont have a vacuum?

-- I found the board stretcher... finally!

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6 posts in 49 days

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