My 1950s era ranch house had two bedrooms added sometime in the 80s (I think). I am in the
process of adding a ceiling fan/fixture to one of the bedrooms and have discovered some unexplained
wiring in the walls and attic. Essentially, there seems to be a bunch of romex 2-wire cables (with a
red and a black conductor, and NO GROUND and no neutral). running all over the place. There are
junction boxes near the light switches with blank cover plates over them, inside of which I can see three
of these cables coming in and being junctioned together (again, red and black, no ground, no neutral).
All cables I’ve found so far seem to have no power running through them (voltage sniffer detects power
in nearby lighting circuit, but nothing in these, which doesn’t mean there isn’t a switch somewhere that
would energize them…). Even more puzzling though is that I have found some of these cables coming
up through the top plate of the wall into the attic and looping back in to the drywall in the ceiling. As in,
it appears that the cables have been glued (there is a puddle of what looks like polyurethane around
where the cable meets the drywall) in to the drywall itself, with no wall or fixture beneath it.
From the attic, it looks like the cables are glued into the drywall in the middle of the room, but from the
room itself there is no indication of what’s going on up above.
There is no evidence of these circuits back at the main service panel for the house. (i.e., no 2-wire
cables coming in to the panel).
Not sure if it’s related, but when I cut a hole in the drywall in the ceiling for my new fan/fixture, the drywall
seemed to have tiny (maybe 18ga?) wires running under the paper on the backside, embedded in the drywall itself. Did
drywall ever have small wires in it for stability/structural reasons? What the heck could those be for? In
cutting the small hole for the fan box, I came into contact with two of these wires and can only assume
there are more…
Could this have been for some kind of heating system? A security system? My inclination is to let sleeping
dogs lie, but I can’t for the life of me figure out what this stuff is or why it’s there. I don’t want to tear all the drywall
off my walls to figure this thing out, but I’m tempted.
Replies
The small wires could possibly be for resistance heating, but more likely some sort of security system. The cabling sounds like it's for smoke detectors or security sensing or some such.
Another possibility for the setup is that it's a sound system and the wires in the drywall somehow make it a massive subwoofer.
If you can read any numbers on the side of the cable, that might give us a clue.
.
Electric radiant ceiling heat.
Still available, but not very popular. Had to Google to see what is still available.
ESWA and Safe-T-Flex are similar to under floor cable systems
Therma Ray are stand alone panels integrated into the ceiling design.
Panelectric heat panels are what you are descibing, wires embedded in drywall.
I guessing the boxes on the walls were for thermostats that have been removed. I'm assuming that you would have noticed a warm ceiling if there was any power going to these, and that they are inactive. I would trace the wires to ensure that they are trully disconnected just be sure.
Ah ha!
Yes! Thanks for the info -- a little google search turned this up:
http://www.drywalltalk.com/f2/electric-heat-sheetrock-980/
Now it all makes sense. Yes, the junction boxes in the two bedrooms must have been for
thermostats. And I forgot to mention in the original post that the wires in the cables were 14ga solid
copper (so it couldn't have drawn that much power). I wonder why it was abandoned. It's too late
to try and make it work again now...
Thanks for the help! Mystery solved!
I'm guessing it was expensive, unreliable, and didn't put out much heat.