Build garden fence on or beside uneven concrete base?

Hello,

I would like to install a double rod panel fence at a height of 1.2m towards the neighbor. My property is about 25cm lower than the neighbor’s.

There is unfortunately a very uneven concrete base at the property boundary, original from the 60s.

The base runs the entire length from the left to the right end with a total slope of about 40cm and unfortunately with some waves and "hills." This makes it difficult to achieve a uniform height offset for the fence posts when mounting on the base without having a large gap under the first few fence panels on the left. Here, I would make core drills with a diameter of about 15cm in the existing base and then mortar the posts in.

An alternative would be to simply buy the fence posts a bit longer and place them directly adjacent to the base on my lower property. However, I don't know if that will hold, since only three sides of the fence post would really have concrete, and the fence post would directly abut the existing concrete base, with no or very little concrete beside it when embedding (see graphic for illustration). I also want to waste as little space as possible since the garden is very narrow.

The next problem I see is that a hedge is supposed to be planted directly next to the fence. So, the ground will have to be dug up again right next to the concreted fence posts for the hedge plants, which could pose a risk that the concrete foundation of the fence posts no longer has enough hold.

The neighbor is basically indifferent as to whether the fence goes on or next to the base.

I just want to find the overall best solution for fence + hedge.

What do you think?

So the thing is straight right now. These few millimeters, maybe even 1-2cm, can be easily compensated.

Build something out of wood yourself, as you can more easily incorporate the unevenness or saw it to fit. In addition, it is also denser than currently and still looks nice. It practically invites you to build it on the existing base.

Hello Frankenländer,

from personal experience, a border fence is always a tricky matter. Who owns the base? You, the neighbor? Does your property boundary run exactly in the middle of the base? First, talk to the neighbor to see how they view it.
If you agree, I would definitely mount the fence system on the base along the property boundary.
The posts can also be screwed onto the concrete; the unevenness/height adjustment can be easily done with a concrete grinder.
Since you have a slope, you have to plan a stepped, slightly offset installation of the fence panels anyway.
The cleanest solution would be to tear off the concrete edge, set the fence posts, and absorb the height difference to the neighbor with curbstones between the posts. No problem at all. Especially if you plan your bed/hedge at the property boundary.

Good luck

It is a terraced house and the fence runs exactly on the boundary. Larger work in the garden is a problem because the garden can only be accessed through the house, so the transport of materials in and out is only possible with increased effort. At the end of the garden is a 2-meter-high wall, which borders a private path. Therefore, tearing down and rebuilding the wall is rather not an option. The problem with the height compensation is that the existing base is sometimes too high, then again too low, and then too high again, so it does not slope evenly.

I just want to find the overall best solution for fence + hedge.

Then I'll ask straight out: why does it have to be a fence if the conditions make it almost impossible? Why not just a narrow hedge and be done with it? Or, if the neighbor is easygoing, talk to them about whether you can put your fence, which you alone pay for, on their lawn at the little wall/concrete base/bed edging.