ᐅ Damp Walls in a New Basement Build – Construction Execution Error?

Created on: 18 Oct 2018 19:30
E
Earth2018
Hello everyone,
I’ll start chronologically:
Background: 3 weeks before day 0, the screed was “laid,” including in the basement.
The basement is a “white tank,” meaning the base slab is waterproof.
Day 0: I notice moisture rising on the plaster in some corners of the basement.
At that time, the plasterers were still fetching water in the basement. The suspicion was therefore a leaking hose or something similar.
Day 1: The underfloor heating is filled with water, so the water cannot be coming from the underfloor heating since it was empty beforehand. The pressure was also constant.
Day 2: The level of moisture on the walls has risen slightly.
Day 5: The underfloor heating is put into operation, including in the basement area with moisture. The hope was that the moisture would decrease due to the warmth.
Day 8: Moisture is still present...

It hasn’t rained since day 0 either...
What do you think? What could this be?
A construction fault? Or does it really take that long for the water to dry?

Corner of a wall with cracks at the lower wall area; black sealing strip on the floor


Close-up of a dusty floor corner with damaged skirting board and dirt on the floor.


Corner area of raw concrete wall and floor; sealing strip at the foot and dust.


Corner area of a concrete wall with dark cracks, dusty floor and a coin as scale


White wall in the corner with a fine, curved line; black cable on the ground.
Earth201819 Oct 2018 08:53
The site manager still believes that the moisture is not coming from the concrete slab but from a spilled bucket, a leaking hose, or something similar. That could also be the case, as there has been a lot of water “tapped” in the area.

A fan will now be installed to dry the affected spot.

We will just wait a few more days.

At the moment, I don’t see the need for an expert surveyor. If the moisture persists or increases, the situation will be clear, and then my builder will be under obligation to act.
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Lumpi_LE
19 Oct 2018 11:15
It can't be coming from the foundation slab, and you can also see that the house is not situated in the groundwater. I also suspect that someone has mixed something with a lot of water, or at least I hope so for your sake.
S
Steven
19 Oct 2018 11:34
Hello Earth

The basement structure looks good. There is no water seeping in from outside anywhere.
Someone made a mess. The moisture is under the screed and needs to be removed. A construction dryer is just the right solution for that. However, make sure to note the electricity consumption. It might become a bit costly.

Steven
Z
Zaba12
19 Oct 2018 11:40
Steven schrieb:
Hello Earth

The structure of the basement looks good. And there is no water that could penetrate from the outside.
Someone made a mess. The moisture is beneath the screed and needs to be removed. A construction dryer is exactly the right solution for that. But keep track of the electricity consumption. It can be costly.

Steven

That is also my assumption, but as a layperson, I didn’t want to say it. However, even one week of drying with a construction dryer won’t be enough. It takes longer than just a few days of drying with a construction dryer.
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Ulrich Fuckert
19 Oct 2018 16:47
A construction dryer is not sufficient here. The damage pattern clearly shows that moisture is present beneath the screed (in the screed insulation layer). Therefore, drying the screed insulation layer must be carried out.
Earth201819 Oct 2018 19:17
Thank you for your comments and assessments.

That would basically mean that the issue is not with the foundation slab.
That would definitely be a huge relief for me.
However, I will only have final certainty after it has rained, and it should not affect the damage pattern.