ᐅ Plot with a change in ground level – boundary wall between neighbors – foundation?
Created on: 10 Jul 2017 19:20
D
DReffects
Hello!
I hope this is roughly the correct section for my question; if not, please feel free to move it.
Situation:
The neighbor’s plot is significantly higher than mine, and their garage was built just 20cm (8 inches) from the property line. Since the development plan actually requires that there be no sudden changes in ground level, the neighbor should have compensated for the height difference with a slope at about 45°. My garden level means there would be a roughly 1.5m (5 feet) wide slope here—of course, at the expense of their plot. So, we agreed that instead of the slope (and demolishing part of the garage...), the neighbor must build a retaining wall on the property line, which also ensures that drainage happens where it’s supposed to.
We have not yet set the final ground level on our side; we plan to lower it by about 70cm (28 inches). Now, the neighbor has dug a trench along the property line, poured concrete into it, and is building a wall on this foundation using hollow blocks that they also plan to fill with concrete later.
If I remove about 70cm (28 inches) of soil on my side, this will expose all but 30cm (12 inches) of their foundation. From my point of view, 30cm (12 inches) is not enough to support a roughly 1.8m (6 feet) high wall along with the adjacent garage and garden.
The neighbor disagrees. Therefore, my question: is there an online calculator somewhere that can determine the required foundation depth? I would rather not have the neighbor’s wall collapse on my children in a year... My construction company has also expressed concerns and does not want to carry out any further earthworks until the wall issue is resolved.
Thank you
I hope this is roughly the correct section for my question; if not, please feel free to move it.
Situation:
The neighbor’s plot is significantly higher than mine, and their garage was built just 20cm (8 inches) from the property line. Since the development plan actually requires that there be no sudden changes in ground level, the neighbor should have compensated for the height difference with a slope at about 45°. My garden level means there would be a roughly 1.5m (5 feet) wide slope here—of course, at the expense of their plot. So, we agreed that instead of the slope (and demolishing part of the garage...), the neighbor must build a retaining wall on the property line, which also ensures that drainage happens where it’s supposed to.
We have not yet set the final ground level on our side; we plan to lower it by about 70cm (28 inches). Now, the neighbor has dug a trench along the property line, poured concrete into it, and is building a wall on this foundation using hollow blocks that they also plan to fill with concrete later.
If I remove about 70cm (28 inches) of soil on my side, this will expose all but 30cm (12 inches) of their foundation. From my point of view, 30cm (12 inches) is not enough to support a roughly 1.8m (6 feet) high wall along with the adjacent garage and garden.
The neighbor disagrees. Therefore, my question: is there an online calculator somewhere that can determine the required foundation depth? I would rather not have the neighbor’s wall collapse on my children in a year... My construction company has also expressed concerns and does not want to carry out any further earthworks until the wall issue is resolved.
Thank you
Alex85 schrieb:
You agreed to build a wall, and no one thought to discuss the heights? Did you decide only after your agreement that you wanted to dig down an additional 70cm (28 inches)?
The wall’s foundation would then no longer be below the frost line. I don’t think that’s a good idea. We originally agreed that he would wait until the final ground level was established. Then suddenly he started, and the construction workers didn’t take no for an answer from me. It was agreed that he would build the wall up to the original ground surface level plus a bit extra on top for water runoff. That requires a proper foundation. Are there, for example, any online calculators for this?
11ant schrieb:
I’m telling you, even a hairdresser would understand that this kind of action without proper procedure is nonsense. Until your excavation and terrain shaping work is finished, you can only build on sand.
If I understand your description correctly, the foundation of a 1.8 m (6 feet) high wall is 1 m (3.3 feet) deep on his side, but only 0.3 m (1 foot) on your side (?) – even if the height on your side is referring to what’s exposed, and on his side only 1.1 m (3.6 feet) sticks out above ground (why so much?), I don’t need a calculator to know this won’t hold.
Check the recent posts, we already discussed something like this about a week ago in the context of a semi-detached house, once with and once without a basement.That’s basically what I think. But the neighbor insists that 30 cm (1 foot) of foundation is enough... I’m just looking for something I can present that clearly explains the situation, even to those not specialized in construction.
To clarify again:
The wall is entirely on his side. Currently, there is still excavation at the property boundary. Once the excavation on my side is removed, the wall directly bordering my property will still be buried about 30 cm (1 foot) in the ground. On his side, there is soil.
Here is a fully professional sketch:
tomtom79 schrieb:
That will never hold, and the expert you need for calculations is called a structural engineer!Is there a recommendation on the best way to approach this without immediately involving the building authorities (building permit / planning permission)? Are there any independent organizations, like the AAA for cars, but for houses?
DReffects schrieb:
I'm just looking for something I can present that clearly explains the situation, even to tradespeople not involved in construction. Just let him follow along here.
Otherwise, he’ll soon be convinced by his own "Leaning Garage of Pisa" :-(
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
11ant schrieb:
Just let him read along here.
Otherwise, his upcoming "Leaning Garage of Pisa" will soon convince him :-( Unfortunately, he doesn’t speak German very well. The house/garage was self-built (I have huge respect for that), but the designs came from a planning office.
From a technical point of view, I was advised as follows:
Tear down the wall
Then dig down about 1.5m (5 feet) starting from my ground level
Install substantial L-shaped steel profiles along the entire width, 200mm (8 inches) high
Estimated cost: 10,000
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