My fiancée found some strange white, hairy material on the corner of our wall. I'm trying to figure out if it's mold, concrete efflorescence, or something else entirely. We live in South Africa, and it's currently winter here, so indoor humidity could be a factor. I've attached some pictures for reference: https://imgur.com/a/abxOReX. Any insights would be greatly appreciated!
3 Answers
Honestly, it kind of looks like mold due to how fluffy it is. Efflorescence usually has a flatter texture like dried salt. You could poke it to see if it crumbles or if it has a soft, flexible feel. If it's soft, it's probably mold.
Have you considered it might be a spider egg sac? Just throwing it out there since it does look kind of strange. Always good to check everything.
It looks like efflorescence, which is just a buildup of salts that comes from moisture seeping through the wall. It's pretty common, especially if there's high humidity around. Just remember, if the humidity issue isn't addressed, it can come back even after treatment! Not hazardous, though.
That's exactly how it goes for me too! Efflorescence pops up all the time where I am, and staying on top of the humidity is crucial.