Peat in soil - pile foundation, well foundation, vibro stone columns

  • Erstellt am 2024-02-05 12:04:40

Rübe1

2024-02-29 16:17:38
  • #1


Only the planning and the structural engineering are commissioned there. Completely separate from the house construction contract. And you need the structural engineering for your columns, no matter how much the "column installer" talks.

Oh yes, since it's a special foundation, in S-H the review structural engineer is also added.... He also takes a few euros.
 

11ant

2024-02-29 17:12:55
  • #2

Oh, you again... do you search for plots with a dowsing rod or why do you always somehow have watery soil problems? I really dislike reading about a "potential general contractor" so early on; better look for builders after the planning stage. And not following the trail of all-inclusive price promises either.

An entire federal state is way too large a search area. That just deepens the confirmation bias that plots are unfathomably hard to find. "Exactly the area we most want to live in" is at best a better search area (and you'd be surprised what’s out there).

The first page of the survey shows the location of the plot, apparently in a newly designated building area. Is that a retention basin directly bordering the surveyed plot to the south, and have you precisely hit the problematic plot?

Drilling only where the result looks less scary, despite expecting heterogeneous subsoil, is definitely a major mistake.

The internet is packed with floor plans. I would put that contractor right at the top of the blacklist.

Basically yes, just with different wording: "Floor plans only after signing." A planning contract—which I definitely advise against!—means here that the builder wants to have a "necessary" architectural planning paid upfront for security, even though he would "credit" it later (if you build with him). A kind of deposit to bind you. As popular as it is dubious.

"To the nearest tenth of a million" would probably be more accurate in this particular case.

Keep searching. It may be possible to somehow tame such a plot too. But you are accepting a foundation cost overhead here that would be completely disproportionate to the construction costs of a normal single-family house. Neither rent to be paid in the meantime nor possible interest rate increases can even remotely reach such dramatic dimensions as the additional foundation effort on this plot would. Please urgently wake up from this nightmare; building land in your federal state only comes with this gigantic catch / drawback! Under no circumstances spend money on placing a house ideally over the boreholes on this plot!
 

Cronos86

2024-02-29 18:55:25
  • #3
The nice thing about vibro-compaction columns is that they are not a special foundation/deep foundation, but a ground improvement. After installation, a load-distributing cushion is installed on top, and the foundation slab is calculated with an improved bedding modulus. It is quite unlikely that this is the only place in the construction area with peat in the subsoil.
 

11ant

2024-02-29 21:01:03
  • #4
If I am correct in assuming that the facility on the neighboring property is a retention basin, then yes and no (we do not know what came first: the soil conditions or the choice of location).
 

Nordlichter

2024-03-01 11:39:06
  • #5
Good morning! Thank you very, very much for your answers!

@ Rübe1

I sent an email to the soil expert and hope he can tell us whether a structural engineer is also needed for this foundation method. We are trying to get as comprehensive a picture as possible of what the foundation on this soil entails, thanks for the hint!



The two plots are located in directly neighboring municipalities, so we didn’t have far to go with the dowsing rod! And bam, a bullseye again.
During the development, peat was found at various spots in the construction area, which we already knew, as it had been communicated quite transparently. But whether the peat is also on this plot (there had been no investigation directly on the plot before) was unknown, it could have worked out well, but it didn’t.

The retention basin (yes exactly, adjoining the plot to the south) was planned and created as part of the development of the construction area. Nobody fenced off an existing water-retaining hole; the hole for the basin was excavated—I have seen pictures of it. Why the basin was created at this exact location is not known to me.

You are definitely right, an entire federal state as a search area is too large and we also realized that this is the area where we want to live. If we now simply assume that this is set, we want to go there ... in this new development area there is peat, in the new development area in the neighboring town there is peat; then maybe you have to swallow this toad (if possible) and accept that the single-family house in this part of the country will cost more than on uncomplicated buildable land elsewhere. Whether it is "more" or "too much" is now the question.

Regarding the foundation costs, is it really so naive to think if the soil here is not suitable, then we try to find out whether it can be made suitable at an affordable price? I’ve been reading through this forum back and forth for months and what is written there about fillings/levelings, L-shaped stones, soil replacement, and pile foundations gives me the feeling that those who find a plot with perfect conditions can count themselves lucky, and everyone else just has to set about optimizing the circumstances.

The basis for the whole project is still whether it is financially feasible in a sensible way. We are still at the starting line with "we want to" and are researching as much as we can, the outcome is still open. But to the tenth of a hundred thousand, for heaven's sake, who could plan down to the tenth of a hundred thousand ... Okay, cents are wishful thinking, a tenth of a hundred thousand is utopian ... subtract a zero from the tenth of a hundred thousand? As soon as the list of expected financial items feels at least roughly complete, I plan to ask the forum what we might still have forgotten.

@ Cronos86

What does an improved bedding modulus for the base plate mean for the scope of work and the costs?
 

11ant

2024-03-01 12:20:20
  • #6

I can well imagine that this is still relatively the worst plot in this development area, and that better ones could be found in the surroundings (they do not necessarily have to be new development areas where you go hunting).

Yes, that is naive – especially because of the wishful thinking of making it affordable. Foundation costs are completely "sunk costs" that do not increase the value of the house even by a crumb, nor the mortgage lending value either. By the way, L-stones are "cosmetics," mainly intended for aesthetic terrain modeling. Their suitability for real slope stabilization is often overestimated. I like to put question marks behind them in each height equal to the L-stones themselves.

Shifting decimal places has nothing to do with subtracting.

That definitely sounds much more reasonable than letting yourself be blackmailed into receiving floor plans only in exchange for a planning contract.
 

Similar topics
18.09.2012Construction of a base slab with frost skirt but without foundation10
29.06.2016Brandenburg Building Regulations / July 1, 2016 - Structural verification engineer no longer required11
16.11.2016Broadband supply for the new development area over my property17
06.06.2017Local bank markets plots - linked deal26
16.11.2017No building land due to new EU native model?168
10.12.2019Building ground suddenly a biotope135
23.11.2019Receive various floor plans for the notary appointment10
20.01.2020Rural new development area near railway tracks or flight path70
09.02.2020Loess Loam & Shell Limestone as Building Ground: Unexpected Expenses / Costs10
02.06.2020New development area - Plot from the municipality18
29.07.2020Vacant lot vs. new development area - how to decide?50
10.11.20202 (dream) properties - financing unclear. Save equity?40
24.03.2021No internet in the new development area - DigiNetz law?28
12.04.2021Land prioritization for application for new development area28
05.08.2021Divide and develop plots themselves24
12.01.2022Union of two plots - redefine the building envelope?20
08.02.2023Which of the two floor plans is better?20
05.09.2023Application for a new development area: Selection of plots41
29.05.2025Plot selection in the new development area for single-family house - ranking61

Oben