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Thanks. Good to know. But probably worth mentioning that, even though you can insulate around knob and tube where local jurisdictions allow it: "K&T wiring is

by mhb 4y ago

Thanks. Good to know. But probably worth mentioning that, even though you can insulate around knob and tube where local jurisdictions allow it: "K&T wiring is designed to dissipate heat into free air, and insulation will disturb this process. Insulation around K&T wires will cause heat to build up, and this creates a fire hazard. The 2008 National Electrical Code (NEC) requires that this wiring system not be covered by insulation."

drjasonharrison 4y ago
I wonder how often this actually is a problem, in that the owner looks at knob and tube wiring and keeps it for the heritage value. My parents were ripping it out in the 1970s from a 1920s home. I know that heritage designations often require using the original construction techniques but do they prevent upgrades to the electrical system? "I'm sorry sir but your grandparents didn't have grounded outlets so you can't install have them either."
- mhb 4y ago
  The problem, at least in my case, is that my 1930 house has k&t wiring and little/no insulation. The easiest way to add insulation would be to blow it in through drilled holes. This is a lot less involved than rewiring the house. I have no affection for the wiring - nostalgic or otherwise. And, yes, vapor issues.
- lazide 4y ago
  Most home insurance won’t insure homes with knob and tube.