ᐅ Building a garden fence on or next to an uneven concrete base?

Hello,

I want to install a 1.2m (4 feet) high welded wire fence towards the neighbor’s property. My plot is about 25cm (10 inches) lower than the neighbor’s.

Along the property boundary, there is unfortunately a very uneven concrete base, original from the 1960s.

The base runs along the entire length from the left to the right end with a total slope of about 40cm (16 inches) and unfortunately with a few waves and “hills.” This makes it difficult to achieve a consistent height offset of the fence posts when mounting on the base, without leaving a big gap under the first few fence panels on the left side. My plan would be to core drill holes of about 15cm (6 inches) diameter into the existing base and then set the posts in mortar.

An alternative would be to buy slightly longer fence posts and install them directly next to the base on my lower ground. But I am unsure if this will be stable, since then only three sides of the post will be surrounded by concrete, and the post will lean directly against the existing concrete base with little or no concrete poured beside it during installation (see attached diagram for illustration). Also, I want to minimize space usage since the garden is very narrow.

The next issue is that a hedge is to be planted directly next to the fence. This means the ground beside the concreted fence posts will have to be dug up again for the hedge plants, which could risk reducing the stability of the fence post foundations.

The neighbor is generally fine whether the fence is installed on the base or beside it.

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

What do you think?

The thing is straight. Those few millimeters, maybe even 1-2cm (0.4-0.8 inches), can be easily compensated for.

Why not build something out of wood yourself? It’s easier to work in or saw to fit any unevenness. Additionally, it’s more insulating than what you currently have and still looks nice. It really makes sense to build it on the existing base.

Hello Frankenländer,

From my own experience, a border fence is always a delicate matter. Who owns the base? You or the neighbor? Does your property boundary run exactly in the middle of the base? First, talk to your neighbor to see how they view it.
If you both agree, I would definitely install the fence system on the base along the property boundary.
The posts can also be screwed onto the concrete; any unevenness or height differences can easily be adjusted with an angle grinder.
Since you have a slope, you will need to plan for a stepwise, slightly offset installation of the fence panels anyway.
The cleanest solution would be to remove the concrete edge, set the fence posts, and compensate for the height difference with curbstones between the posts. This is no problem, especially if you plan a flower bed or hedge along the property line.

Good luck

This is a terraced house, and the fence runs exactly on the boundary line. Larger gardening work is problematic because the garden is only accessible through the house, so transporting materials in and out requires extra effort. At the end of the garden, there is a 2-meter (6.6 feet) high wall adjacent to a private path. Therefore, demolishing and rebuilding the wall is unlikely.

The issue with leveling is that the existing foundation is sometimes too high, then too low, and then too high again, so it does not slope evenly.

Frankenländer schrieb:

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

Then I'll ask plainly: why does it have to be a fence when the conditions make it almost impossible?
Why not just a narrow hedge and call it a day?
Or, if the neighbor is easygoing, talk to them about whether you can place your fence, which you alone are paying for, on their lawn next to the low wall/concrete base/flower bed edging.