Hello everyone, we built our house four years ago and now need help with a problem involving a damp wall.
Since last year, we have noticed small mold spots in the office along the lower part of the wall, as you can see in these pictures:
We initially thought the issue was due to insufficient ventilation on our part.
For the past one and a half months, we have also noticed that the outside wall is damp, as shown here:
My first thought was that there might be a problem with the drainage, so I flushed the pipes using a drain cleaning hose from Kärcher.
However, the water never backed up into or over the gutter, and I did not feel any resistance while flushing.
After two weeks without rain, the damp wall issue did not improve, so I uncovered the underground drainage pipe in the corner and found it to be intact and sealed:
I poured water from above into the downpipe for two hours, and no water escaped anywhere.
A neighbor told me I had made two errors with the pipes, connecting them the wrong way around and using the wrong angle fitting.
However, he said that this could not explain the damp wall problem.
He suspected that the moisture might be coming either from the roof (possibly a damaged roof tile) or from the ground (due to missing or faulty waterproofing on the masonry).
As far as we can tell, the roof is in good condition:
The builder sent someone to remove a stone from the wall to check whether the waterproofing was installed correctly:
They saw that there is a membrane on the red brick, but they did not have an explanation for the source of the water and suspected it might be coming from the downpipe.
They said they could not do more for us and recommended that we hire a building inspector.
Unfortunately, this response was not very helpful to us since the problem persists and we do not know whether we caused it ourselves.
Also, hiring an inspector would likely be expensive, and we would have to pay if the problem turned out to be due to an installation error on our part in the drainage system.
Inside that area, there is no water connection, only underfloor heating, and the water pressure in the building has remained stable at 1.6 bar for a long time.
As you can see here, the wall and tiles (only in the corner) are damp:
What is also strange is that below the downpipe there is cement with a slope towards the house:
We were told that this can happen sometimes; although it is not ideal, it should not explain the dampness in the wall since everything is now exposed.
The hole has been open for two weeks, and no rainwater has accumulated there in one day (the spot is also under a roof overhang).
I also tried drying the wall with a fan heater, which only helped to a limited extent; after one day the wall was damp again.
What do you think—is the moisture coming from the soil due to missing or faulty waterproofing of the masonry?
We would appreciate any help or ideas as we are running out of options.
Since last year, we have noticed small mold spots in the office along the lower part of the wall, as you can see in these pictures:
We initially thought the issue was due to insufficient ventilation on our part.
For the past one and a half months, we have also noticed that the outside wall is damp, as shown here:
My first thought was that there might be a problem with the drainage, so I flushed the pipes using a drain cleaning hose from Kärcher.
However, the water never backed up into or over the gutter, and I did not feel any resistance while flushing.
After two weeks without rain, the damp wall issue did not improve, so I uncovered the underground drainage pipe in the corner and found it to be intact and sealed:
I poured water from above into the downpipe for two hours, and no water escaped anywhere.
A neighbor told me I had made two errors with the pipes, connecting them the wrong way around and using the wrong angle fitting.
However, he said that this could not explain the damp wall problem.
He suspected that the moisture might be coming either from the roof (possibly a damaged roof tile) or from the ground (due to missing or faulty waterproofing on the masonry).
As far as we can tell, the roof is in good condition:
The builder sent someone to remove a stone from the wall to check whether the waterproofing was installed correctly:
They saw that there is a membrane on the red brick, but they did not have an explanation for the source of the water and suspected it might be coming from the downpipe.
They said they could not do more for us and recommended that we hire a building inspector.
Unfortunately, this response was not very helpful to us since the problem persists and we do not know whether we caused it ourselves.
Also, hiring an inspector would likely be expensive, and we would have to pay if the problem turned out to be due to an installation error on our part in the drainage system.
Inside that area, there is no water connection, only underfloor heating, and the water pressure in the building has remained stable at 1.6 bar for a long time.
As you can see here, the wall and tiles (only in the corner) are damp:
What is also strange is that below the downpipe there is cement with a slope towards the house:
We were told that this can happen sometimes; although it is not ideal, it should not explain the dampness in the wall since everything is now exposed.
The hole has been open for two weeks, and no rainwater has accumulated there in one day (the spot is also under a roof overhang).
I also tried drying the wall with a fan heater, which only helped to a limited extent; after one day the wall was damp again.
What do you think—is the moisture coming from the soil due to missing or faulty waterproofing of the masonry?
We would appreciate any help or ideas as we are running out of options.
K
Knüllwald4 Jul 2022 12:51Basically, I would say that one issue is the lack of a moisture barrier against the wall. A dimpled membrane would definitely help here to allow air circulation.
Furthermore, without knowing the house, I would guess that the short side of the house faces west, meaning it is exposed to the weather. Driving rain hits the corner, seeps down to the concrete, and rises up the wall. The missing slope of the paving worsens the situation. Or there might even be a slope toward the house wall.
In such corners, the slope should be steeper to ensure water really drains away and doesn’t accumulate there. The combination of the gutter and the corner of the house causes water to collect precisely in that spot.
Furthermore, without knowing the house, I would guess that the short side of the house faces west, meaning it is exposed to the weather. Driving rain hits the corner, seeps down to the concrete, and rises up the wall. The missing slope of the paving worsens the situation. Or there might even be a slope toward the house wall.
In such corners, the slope should be steeper to ensure water really drains away and doesn’t accumulate there. The combination of the gutter and the corner of the house causes water to collect precisely in that spot.
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