Sealing the basement - a few questions

Hello,
we have now inherited a house that we would like to renovate and I have a few questions about the basement and its sealing against water from the outside.

The house was built around 1930. However, in the meantime, a part was also added. In any case, the basement, as was common in the past, consists of fieldstones on which the house was probably built.

The basement is located almost in the center of the house, I have drawn a small sketch of it. Furthermore, the basement interior has been newly plastered almost everywhere except for the gable side, which is still partially unplastered.

As you can see there, there is only one wall from which water can penetrate from the outside, namely from the gable side. When it rained heavily recently, I noticed that quite a lot of water ran through this wall, exactly where it is still unplastered.
After that, I excavated the basement outside to see where the water was coming in. There I found one or two spots that seemed suspicious to me.
I assume that the water was pressed against the house wall and then seeped into the basement through the partially porous mortar.

Now I want to seal the whole thing, of course, so that I can backfill it again and have a reasonably dry basement. And now I wanted to get some advice on how to proceed best.

So I actually wanted to first remove all loose mortar or gravel between the fieldstones from the outside to then close the joints with cement mortar and then plaster the outside wall, and after that, I would apply a bitumen layer.

Is this sufficient, or do I need to install a dimpled membrane (Noppenbahn) or something else, for example?

Or how would you do the whole thing?

Hello kay123,

as far as I understand you are doing everything yourself, but judging by your questions you are not a professional?

Without having seen the object:
- do you want to have the basement later within the heated perimeter? (insulation)
- Removing loose parts from the exterior wall and plastering (so that you have a flat surface for the sealing or insulation) sounds good, but I would inquire about what kind of plaster should be applied and how long it needs to dry (on the one hand otherwise the possibly additional layers will not adhere and on the other hand the plaster itself can hardly dry afterward)
- Then I would have a waterproofing layer applied (the contractor is also liable for the execution!). I think just a bitumen coating would be too risky for me, I would rather assume welded, fully glued bitumen sheets).
- Insulation if desired (Perimeterdämmung)
- Studded membrane or alternatively filter plates
- If a lot of water is still expected, a drainage pipe.

Good luck

K.Brodbeck

Noppenbahn is good! Seal the masonry beforehand, for example generously with waterproof slurry or renovation plaster. However, water may also be pressing through the ground?