How to insulate around old, brittle electrical wiring
Old electrical wires do not handle heat well and can overheat if you compact insulation around them. Because the wiring is often so brittle that it breaks or cracks just from being touched, you should carefully maneuver it out of the way and strap it to the studs. If that is impossible, splice the connections into a junction box and run new Romex cable that can be safely buried in the insulation.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
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- 1Wrapping the frayed area with electrical tapeDid this help you?
- 2Maneuvering and strapping wires to studs to get them out of the wayDid this help you?
- 3Splicing connections into an accessible junction box and adding new Romex cableDid this help you?
- 4Running a completely new electrical cable with a ground from the fixture to the switchDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“That's very old wiring. Try not to touch it too much or will start cracking further.”source ↗
“You do not want to heavily insulated these wires. They don't handle heat as well so compacting insulation around it can cause it to heat up to higher temperatures.”source ↗
“If you can maneuver it around and strap it to studs to get it out of the way, you should try to do that. If it's not possible, you can always splice connections into a junction box and add new romex cable and then you can bury that new romex cable with the insulation.”source ↗
“Originally the vent fan had the silver flat wire going to the ground screw. However that wire was so brittle that even touching it caused it to break off so now it’s broken off to inside the shell of the cable.”source ↗