Could there be mold under the plaster in the basement?

[Ivar83]

The walls in the basement are crumbling due to moisture from outside. In the laundry room, large bubbles are forming. When I pulled off a large piece, it looks like mold under the crust. Could this be accurate? What else could it be? It glitters and looks like snow.

 

[Stefan N]

No, it's salt efflorescence, not mold.

 

[Intet]

Yep. Lick it and you'll see that it tastes salty.

 

[b8q]

Agree with the previous post. Additionally, it is a sign that you need to redo the drainage, and also remove the too dense paint on the basement wall and replace it with a paint that can let through moisture, such as silicate paint or lime paint.

 

[g.kraft]

As already mentioned, it is not mold. However, it is due to moisture, so you should still investigate why it occurs.

If you don't have pipes in the wall/ceiling there, it is likely coming from outside. Either a drainage problem, or surface water from a downspout or something similar is pooling against the wall.

It may also be that a completely impermeable paint was used on the basement wall. There should be a diffusion-open paint that allows moisture in the concrete to evaporate. If it can only evaporate through cracks in the paint, you will get moisture and salt migrations there.

 

[Manganbangan]

The water pushing through the wall carries salts and minerals from the soil outside, and when the water evaporates, it leaves behind, as previously mentioned, a salt deposit. Even if the wall is unpainted, this will happen as long as the drainage is poor. Be aware that this can also occur on interior walls if moisture presses through an uninsulated concrete slab, typical for older houses.

 

[Ivar83]

Thank you so much for all the answers! Really nice of you.
The house has recently been drained, so hopefully, we will avoid further problems.

 

[Manganbangan]

Something I encounter daily is customers who have drained but do not "reset" the walls afterwards. Something that looks current may be ten years old.

 

[g.kraft]

Thank you so much for all the answers! Really nice of you.
The house has recently been drained, so hopefully, we'll avoid further problems.

Probably old symptoms that remain. Just scrape clean and paint.

If you plan to wait with painting, still scrape clean now to see if it comes back in case there are any other causes.

You can also circle spots with a pencil to confirm that they don't grow or are new.

Read up a bit on paint for basements so that it will go well to make it nice again. Good luck!