It looks slightly metallic. It glints slightly in my headlamp. Like black snow crystals.

I found it under the insulation. See attached pic.


weird black attic dirt

  • 1
    How old is the house.
    – Kris
    May 7, 2018 at 2:39
  • 1
    Also what type of roof does the house have?
    – Tyson
    May 7, 2018 at 2:53
  • Built in the early 90's. May 7, 2018 at 17:29

1 Answer 1


That material is most likely grit that came off the shingles of the roof. It could have gotten there during a roof replacement when old shingles were removed and roof sheathing was also replaced.

If the material is localized in just one area it is possible it got there even from the original construction if shingles were piled and opened on the roof before all the sheathing was installed.

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