Sealing garden wall to neighbor

Dear all,

We have been living in our semi-detached house from the developer - turnkey - for a good six months now. This includes a small garden. The whole thing is located in an existing residential area. Since the plots have different levels relative to the streets, there is a height difference to the neighboring properties.

At the back, there was already a stone wall on a concrete foundation (calcium silicate brick?) next to the neighbor before construction began - this can be seen from a slightly greater distance in the first photo. Unfortunately, I don’t have a better photo.

During the construction phase, the wall was simply backfilled with soil to raise the level on our side. Before the topsoil was placed, a dimpled membrane was laid against the lowest row of stones, but only up to the beginning of the foundation - see another photo.

The neighbor now claims that the wall on our side is insufficiently waterproofed and that efflorescence is appearing on her side.

Could this be related? The wall was also exposed to the weather before, wasn’t it? Is waterproofing required here or can it be demanded by her? What would proper waterproofing look like in this case?

Of course, our developer says that everything is correct and denies any fault.

If it is relevant: the wall stands about one third on our property.

I am very grateful for any tips and advice!

Happy Father’s Day/Men’s Day to you all!

Hi,

yes, it can already change with her. Previously, the water could drain away and now it stands against the wall after the rain. The dimpled membrane is supposed to promote the drainage of the water and is therefore initially correct.

But if the water now stands there, it can only diffuse in the direction of the neighbor and there are then efflorescences.

Furthermore, she can basically demand from you to take appropriate measures there, because you are the cause of her problem, meaning that only because you backfill, she has a defect. It is not clear now whether the efflorescences really only appeared after your action, but of course no one wants a dispute.

My suggestion to you would be to remove the ground there again, let the wall dry out, and apply a mineral waterproof slurry. Then the dimpled membrane (better with fleece) and the ground again.

From the general contractor’s side, he has not done anything wrong at first. He could have informed you in advance so that the damage would not have occurred - but the risk and cost responsibility lies with the client.

Now you wrote above that you bought the house from a developer – so he had the plot and built a house on it which you then bought including the plot? Then the plot risk was with him before your purchase and accordingly also the obligation to protect this wall.

I think that trying to make a claim to the developer is at least worth a try.

If you need help with the wording, I’m happy to help.

Thank you for your detailed response! That largely aligns with my thoughts and ideas. And yes, we purchased the house including the property (among other things, with 20cm of fresh topsoil) from the developer as a whole.

Since we have had no problems with the neighbors so far and have addressed the matter very amicably, we also want to find a reasonable and long-term solution out of our own interest. And of course, preferably before we properly plant the beds in front of the wall.

What would be considered a reasonable sealing here? Our developer probably won't come up with a solution on their own...

Thanks again!

Some points came to my mind as well.

- Why is the wall standing on one-third of your property?
- The wall "must not" remain so ugly. Walls facing inhabited areas must, in my opinion, at least be designed in a visually "acceptable" manner if there are complaints.

The last point could then be discussed together with the neighbor to develop a technically good and visually appealing solution and then fairly share the costs. Is that called a win-win situation? ;)

Some points came to mind. - Why is the wall standing one third on your property? - The wall "must not" remain that ugly. Walls facing inhabited areas must, in my opinion, at least be designed to be visually "acceptable" in case of complaints.

According to the neighbor, the wall was already there when they bought the house themselves a few years ago. But I wouldn't make a fuss about a few centimeters. We want to put a trellis or something like that in front of it anyway in the end. But if the wall has to be "presentable," there is still some leeway to come to an agreement together if the developer doesn't take further action here. The only question remaining is what a proper sealing would look like here. And how deep?

My suggestion to you would be to remove the floor there again, let the wall dry out, and apply a mineral waterproof slurry. Then dimpled membrane (better with fleece) and put the floor back on.

I have only just read that now. I had feared something along those lines. How deep would you then waterproof: only the stones a few centimeters above the concrete base, or also the concrete base?

Let's see what the builder says. The neighbor had apparently already contacted the builder directly during the construction phase, but without response.

In addition, in the end it will affect not only us but also the neighbors in the other semi-detached house. They just haven’t moved in yet...