Background: I had some plumbing work done and old walls cut out from this area. New drywall was put in back in February. Today I noticed white powdery stuff on power outlets — not just in the area directly around the new drywall but other nearby spots.

The drywall on the ceiling has powder on it that I can wipe off with my hands. So do some of the nearby walls that WEREN’T cut out. I already painted (crappily) the wall that was redone and that one isn’t powdering anymore. I’d already wiped it pretty clean.

Is this just leftover drywall dust that’s kicking up around various places, even where there’s no new drywall? Or do I have efflorescence? Is it even possible for efflorescence to come out of walls?

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2 Answers 2


It is impossible to tell what exactly that powder is.

Efflorescence would be accompanied with the presence of moisture. You have not indicated any moisture was found.

Drywall work creates fine dust that gets everywhere. So, an educated guess is that is drywall dust.

  • Thank you. I’m fully paranoid about moisture right now. I do have some efflorescence coming from my chimney that I need looked at. But yeah no obvious signs of moisture. Thank you.
    – user176121
    Nov 12, 2023 at 17:19

Plaster dust. If it bothers you, give the area a quick swipe with a slightly damp rag. But realistically, if you're going to paying, the paint will absorb the dust and solve this for you.

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