Basement and moisture on plaster/wall

[blåbär83]

Hello! We have plaster that is coming off the wall in the basement. I'm a bit of a novice with this, and what could be causing it. Of course, there is some moisture in the basement, and maybe a less than ideal plaster used? I am grateful for any suggestions/tips on how to handle this/improve it.

Hard to get a good picture, but it's plaster on the outside and brick inside.

 

[Bart]

Looks like moisture penetration from outside through the wall is causing the plaster to peel. How old is the drainage?

 

[Centano]

What does it look like on the outside of the wall?

 

[Stefan N]

no point in redoing it until you've solved the actual problem.

 

[blåbär83]

Thanks for the quick replies! It's not really an exterior wall, but rather a partition wall at an angle to the exterior wall. I forgot to mention that in the first post. Drainage was done around the turn of the millennium.

 

[Bart]

Do you have any way to measure moisture in the wall? If only to rule out water somehow getting into the wall?

 

[Stefan N]

It's an interior wall so it does absorb through the tile.

 

[Bart]

It feels like the plaster would come off further down then too?

 

[Drburr]

Probably being absorbed from below if it's an interior wall, there's really nothing to do about it, I have the same at home, I've plastered and left it unpainted. There are efflorescences but it doesn't look as bad as peeling paint.

 

[gaia]

The ground under the cellar floor, like a concrete slab, is never completely dry. It contains ground moisture that can travel through brick and concrete up into walls via capillary action. This cannot be remedied by drainage. However, one can replaster with suitable plaster that was originally used and paint with a paint that allows moisture to evaporate inward. This helps against common moderate moisture migration.

It looks like something dense has been used as spackling compound along the floor, causing the migration to continue upwards. If that is the case, the dense patch or crust along the floor should be removed and replastered with the original type of plaster (lime plaster?) and painted with breathable paint like silicate or lime paint.

 

[neo11]

Scrape/chip away loose plaster.
Buy 3 mm c mortar, thoroughly pre-wet and apply 3 mm.
The day after, pre-wet again and apply, so you reach the existing wall.
And brush the plaster after 20 minutes.

 

[blåbär83]

It's an interior wall so it does absorb through the plate.

Thank you! Yes, that's likely.

 

[blåbär83]

The ground under the cellar floor, like a concrete slab, is never bone dry. It contains ground moisture that can travel through brick, concrete up into the wall with capillary force. You can't drain away from that. However, you can replaster with suitable plaster that was originally there and paint with a paint that allows the moisture that evaporates inward. This helps against a common moderate moisture migration.

It looks like something dense was used to fill near the floor so the migration continued upward. If that's the case, then the dense repair layer or crust near the floor should be removed and replastered with the original type of plaster (lime plaster?) and painted with a breathable paint like silicate or lime paint.

Aha, thanks for the great input!!

 

[blåbär83]

Scrape/chisel away loose plaster.
Buy 3 mm c mortar, thoroughly pre-water and apply 3 mm.
The day after, pre-water again and apply, so you reach out to the existing wall.
And brush the plaster after 20 min.

Ah! Good input, thanks for the tips! Will consider doing that

 

[blåbär83]

Do you have any way to measure moisture in the wall? If nothing else, to rule out that water is somehow getting into the wall?

Yes, I can do that, good tip! I don't think it should be any other water/that water would be getting into this particular wall, but good to be able to rule out of course.