I was using 6 month old paint to paint a tiny room in my house, the paint was first stored in the attic and then it was stored in the garage for a full week before I started painting. The white paint was kinda hard to mix but I thought that was normal.

After painting a couple walls and the paint was almost finished, I found some black dots on the wall. I smudged it off with a towel and it turned brownish. At first I thought it was some other paint that I had used before (6 months ago) and some drops might have fallen in the white paint. Then I noticed some black brownish marks on the inside of the opening lid.

The paint seemed normal and also smelt normal after opening and painting it on the walls, but the lid was covered with some black stuff. I also thought it was that same black paint since there were some black paint spots on the outside of the lid but now I'm doubting it.

The first layer of paint has already dried by now, it doesn't smell weird it just smells like paint after painting. There are no leaks, no stains, or currently any signs of mold. I opened the window so the place is not humid at all.

Have I put moldy paint on my walls, and if so, what should I do now?

  • 2
    I’m voting to close this question because the only way to know for sure that it's mold (and a harmful one at that) is to have a sample tested at a local lab.
    – FreeMan
    Feb 13 at 13:39
  • How was it mixed? A stir stick, a mixer? Paint has a lot of ingredients which is why paint stores use shakers to mix the can/bucket up.
    – matt.
    Feb 13 at 13:59
  • A stir stick was used.
    – stella
    Feb 13 at 14:03
  • I would say that more than likely the paint was not thoroughly mixed and what you're seeing is bits of pigment. I would either take the can to a paint store and have it shaken or use a mixer on a drill and mix it up well. Especially since you said it was hard to mix. The solids that are in paint will settle to the bottom and can become difficult to properly mix.
    – matt.
    Feb 13 at 14:45
  • I have never seen mold on paint. I suspect that the colour you had was off-white sort of greyish. So the spots you see are pigment. IT just needed a better stir. Its best to use a drill based one or even take the can to your local paint shop and they can shake it. Feb 13 at 22:27

2 Answers 2


Fungal spores are everywhere, and you are breathing them right now. If you have a surface with the right conditions for mold to grow on it, mold will grow. It does not matter if the mold was in the paint or not, because spores will land on the paint immediately after applying it anyway. Again, it's all about the conditions: warm, moist, and dark, like the condition in a bathroom right after taking a hot shower without the extractor working.

Having said that, I can't imagine fungi would be able to grow inside of a can of latex paint. Fungi require oxygen to grow, and if you had a lot of air in the can, the paint would have gone bad.

In any case, if mold does end up growing on that wall, use diluted bleach on a a sprayer and clean it up.


If you are not sure about the paint, toss it and get new one. Opened cans can develop mold, especially if they had a lot of air under the lid.

As for paint already on the wall - did you use primer first, specifically a primer with anti-fungal agent? If not, consider applying a coat of antifungal primer on the paint you just laid down, then paint it again with fresh paint.

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