I was about to start cleaning when I noticed this white powder/dust coming out of the baseboard of my kitchen area and I was wondering what it might be. The powder seems quite fine and it very faintly smells like something sweet but used in construction. I have seen similar threads mentioning efflorescence but it does not really look similar to me and this is the first time in my 3 years living here that I saw this powder.

What's interesting is that the powder was being pushed towards the inside of the room almost as if there is a draft going through the baseboard/floor into the room. The dust only appeared on this one part of the baseboard and in no other room either. The wall is an inner wall and the part near the baseboard is some kind of drywall used to route electrical wiring.

I haven't done any renovations or ventilation changes in my apartment for a while and there were no audible renovations happening in the house for a few months at least either.



  • "it very faintly smells like something sweet " Do you have powdered sugar in your pantry? And kids? Commented May 7, 2020 at 14:43
  • @SteveWellens I do have powdered sugar but its on the opposite side of the room and I definitely have no kids. After smelling the sugar as well I can say it does not smell like the powder.
    – Naverritus
    Commented May 7, 2020 at 15:17
  • Whatever it is, it looks to me like it's being sucked out or blown out - not just falling out on its own. Notice how streaky it is, with "voids" on the away-from-the-wall-side of chair & table legs that are in the picture.
    – SteveSh
    Commented May 7, 2020 at 18:18

3 Answers 3


It looks like drywall dust. There were probably cuts made with a rotary tool which left dust inside the wall, and now it's working out, possibly due to air pressure in the wall from an HVAC duct or just environmental air surges.

I'd run a strong vacuum sealed against the joint with rags. That should pull most of it out, though you'll still probably see some residual dust for a while.


We had or tornado swirl around our home the other night. The next day we noticed white powder on at least four of our exterior walls where it looks like the pressure from the wind pushed drywall dust out from under the baseboards onto the wood floor


"upstairs neighbors being more active lately" seems very likely to be related. Maybe they are doing a kitchen remodel that both involved dry wall (creating dust) and opening a wall or the floor above (change in air flow). Go ask them what they are doing

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