Is a damp basement okay? (120 digits)

Hello everyone,

we are considering buying a single-family house from 1935. Brick settler house.
According to our surveyor, the basement has damp but not wet walls. At foot height, he measured 120 Digits, at about hip height only 55/60 Digits.
The air already smelled very damp/cool. But no mold, no mustiness, no newly painted walls. Floor tiled. The sellers say there was never any mold although laundry was even hung up.

The (paid by us) surveyor says it is not a problem, this was intentional, a damp basement so that the house above remains dry. That is also true, everything is dry upstairs. We shouldn’t worry, harmless salts might effloresce. The basement just needs to be used as intended, so not for clothes or files, but for preserves, bottles, etc.

The basement ceiling is not insulated yet, but the exterior walls on the ground and upper floor, so everything above, are already insulated, very well even.
Currently, there is a brand-new gas heating system installed.

What is your assessment? Are the values still okay? On the internet, there are also critical classifications. Unfortunately, the material of the basement wall is unknown to me. According to the surveyor, it is moisture penetrating through the wall from outside, not groundwater.

What would, roughly, a professional waterproofing from the outside cost for a house with an area of about 50 sqm?
More like 10,000 or 40,000 euros?

Thanks for your assessment!

Best regards

How are the conditions overall? Full basement or partially at ground level? On a slope or not? I can only report from our house built in 1930 that it is also the case that the basement is wet or becomes wet depending on the weather. When the groundwater level is high and it rains a lot, water sometimes pushes up through the concrete floor. It’s the same with the surrounding neighbors; one even has a sort of well in the basement where he channels the water. I also know of other old hillside houses where depending on the season almost a stream flows through. Nevertheless, they all stand and do not mold. They were mostly built with the water in mind and therefore are not insulated later in the basement. If you seal something there, it should definitely be professionally planned so that you don’t accidentally make something worse than it is. I can’t say anything about prices... so far we live with the water.

Thank you for your assessment. It is fully basemented, no slope, everything without gradient. A real visible intrusion of water probably never occurred. Then it seems we can manage with that after all.

We also have a basement like that in our settlement house. Shoes and other textile items mold quickly, everything else does not. We insulated about 50% of the basement walls from the outside, since these were overbuilt with an extension and would no longer be accessible afterward. We thought it would be better to do these walls right away. But that was not very smart; there is now mold on the walls in some places. Fortunately, it is not severe but rather just a visual problem. But on the uninsulated walls, we have no problems at all.

The house has stood for 90 years with the basement, and it will manage for another 90 years as well.