Saturday, February 7, 2009

Electrical scare

Sparks and smoke erupted spontaneously from a fissure in the wall one day, recently. After a quick call to the fire department and shutting off the circuit breakers for several suspect circuits in the vicinity of the fissure, we set about restoring the status quo. These pictures follow the sequence of repairs:

Several firemen arrived, filling the foyer where the incident happened. I had the ladder already in place, and one of the firemen climbed up and pulled down the piece of plaster from behind which the sparks had flown. It was about a square foot in size, and had been separated from the wall due to what we had thought was a condition of rain water infiltrating into the walls from outside and causing efflorescence, i.e. pushing salt crystals out with the water vapor to the interior surfaces of the walls. The exterior walls were sealed several years ago and we have been postponing repairs and repainting to be sure the water infiltration and efflorescence had stopped. One of the firemen followed me up into the attic with his heat detector to verify that no embers were smoldering in the wood framing there.

When he pulled off the plaster chunk, 2 rusted sections of metal electrical conduit were exposed. It had indeed been raining, and there was an active leak coming through the limestone crown moulding and right into the damaged zone. This leak, however, was not from the exterior walls, but from the roof. Over the course of many years, the conduit rusted and it's interior surface became abrasive. The electrical wires inside are subject to micro-movement due to the alternating current they carry, and the plastic insulation on the wires finally wore through, allowing the copper conductor to touch the conduit, creating sparks and further melting the plastic insulation.

Water also ran down into the switch box below:

I cut back the rusted conduit, removed the old switches, located the junction box in the attic where the (6)wires were spliced, and pulled in 6 new conductors through the old conduit, and installed new switches, sparing myself the daunting challenge of removing more plaster or even the crown moulding.

Then I patched the plaster and painted it with a "near" matching color until such time as we undertake to repair all the other efflorescence and repaint the rest of the room.


We then began the roof work detailed in the post below (see January 16), in the hope that further roof leaks can be prevented. That led to a whole new project as well.

No comments: