For quite some time I've been noticing what appeared to be water marks around a switch box on a second floor interior hallway wall. At first they were fairly light, so much so I thought it might just be some strange drywall discoloring. Lately it has gotten much worse and I originally thought it might be some leakage from the attic fan on the roof but after going into the attic to investigate, there was no leakage coming from the roof. That was a week ago.
By chance, I happened to be installing a whole house fan this weekend and had to move the electrical in the attic so I had to cut into some conduit to relocate the wiring. When I cut into one of the conduits going to that switch box, I saw black/rust water come out onto the floor of the attic. The inside was all wet.
One end of this conduit terminates at that switch box and the other end at the opposite wall in an outlet. That wall has the garage on the other end.
I took out a 5-6 foot section between the wet part where the conduit turns to go down into the interior hall wall and the part that goes to the other wall. I didn't see any signs of water at the other end I cut closer to the other wall. This seems to be collecting toward the inside wall end.
That piece conduit has no openings or unions near that wall. The closest union was on the other end where I didn't see any water.
Does anyone have any ideas on how this is happening?
I'm including pictures for anyone willing to make a guess. I see a big rust spot on the floor of the box under the second to the right however, the conduit on the far left is the one with the water - you can even see water sitting on the wire nut (pictured).
By the way, there is no evidence of leakage from the roof anywhere. The water just seems to magically appear in that part of the conduit. What gives??
Water in conduit:
Showing proximity to wall entry:
This is the other end closer to the other wall about 5 feet away from the water. This is the closest opening in the conduit until it gets to the switch box in the wall. If water was seeping in at this point I would think I would see some evidence here:
Here's a wide shot showing both ends:
The opened wall:
Water in the nut on the far left: