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. Whats 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.

Here are a few pictures of the powder. Let me know if more information is necessary



  • 1
    Have you done any renovations that might had loosened or shifted construction dust? Have you changed any ventilation or added a whole house fan? – JACK May 7 '20 at 12:04
  • 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. – Naverritus May 7 '20 at 13:14
  • I would keep an eye out for insects, more common in exterior walls , interesting that there is apparently airflow on an interior wall, sealing any wiring and pipes that enter that wall will provide a opportunity to inspect under & over for evidence of bugs, the only thing I can think of is a washer dryer vibrating causing some movement because insects don’t normally chew Sheetrock but I have seen mice and squirrels chew through it. – Ed Beal May 7 '20 at 13:22
  • "it very faintly smells like something sweet " Do you have powdered sugar in your pantry? And kids? – Steve Wellens May 7 '20 at 14:43
  • @EdBeal I will keep that in mind but now that you mentioned vibration I do remember my upstairs neighbors being more active lately. I am going to check the next time I hear them. – Naverritus May 7 '20 at 15:15

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.

  • I guess that's most likely the reason. I will try to vacuum it out as best as possible and see if it comes back. Thanks! – Naverritus May 7 '20 at 15:22

"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


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

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