Sealing garden wall to neighbor

So I would check the elevation at your neighbor's place. The concrete should already have been "underground" there and in the previous situation. Therefore, I think the area is sufficient for the material that was piled up. The stuff could be applied with a brush, that's a job anyone can do and relatively inexpensive. I don't think more can be expected for such a wall. I mean, on your side the adhesive is still oozing out, so that is certainly sufficient. If you want to spend a few euros more, you can use a slurry that is plastic-modified. I can dig up a datasheet at work on Monday. I think it was around 40€ per bag.

Agree: she will have it nicely plastered, and in return you ignore the "assault" and seal further down. That way everyone is helped.

So I would check the elevation level at your neighbor’s. The concrete should already have been “underground” for her and in the previous situation. Therefore, I think the area is sufficient to cover what was piled up. You could apply the stuff with a brush; that’s a job anyone can do and relatively inexpensive. I don’t think more is to be expected for a wall like this. I mean, on your side the adhesive is still oozing out, so it’s certainly sufficient. If you want to spend a few euros more, you can use a slurry that is plastic-modified. I can dig up a data sheet at work on Monday. I think that was about 40€ per sack.

The base/concrete foundation at the neighbor’s is exposed about 30-40cm. It was the same on our side before construction started. I zoomed in on the only photo from that time and attached it.

I don’t even know what it really is under the stones?! Could they also be prefabricated slightly trapezoidal base stones made of concrete? Would they also need to be sealed if they were previously exposed and are now buried? Then I would have to seal 60-70cm deep in the end, which would be significantly more complicated than just the bottom row of stones.

As for us coming to an agreement if the developer has nothing to contribute, I’m not worried at all.

Yes, I would seal everything that was previously exposed.

1. Why do you fill up the terrain without necessity? 2. Why don't you seal before installing a studded membrane?

Solution: Dig out to 20 cm below the masonry stones, then apply a smooth coat. Then apply cold coating up to the top of the terrain, then fleece and studded membrane. Then the wall must be plastered (service from the neighbor).