[distance1323]

Electricians have been installing can lights throughout the house. When the sheetrock comes down there is a black charcoal/soot like material on the top of it. It does smear off and has 'flaky' type layering to it. It's been on every piece that has come down from various parts of the house. Electrician said the ceiling has double sheetrock. The insulation that comes down as well is not discolored and appears normal. Any idea what this is?

 

[joed]

Without images it's hard to know, but black is often times mold.

 

[Bud9051]

Why the double sheetrock? Was there fire damage someone covered up?

What type of heating and does a chimney pass through the attic?

Bud

 

[Gymschu]

If it's an older house and you live in a colder climate, it could be coal dust that came from burning coal in a coal furnace. It found its' way onto just about everything back in the day. I've opened up many a ceiling only to be greeted by coal dust. Just a possibility.