Excerpt from soil report: soil assessment and recommendations

Hello everyone,

I am new here and currently planning the construction of a semi-detached house in Lower Saxony. For this purpose, I have had a soil survey carried out on my property. Unfortunately, I cannot determine from this whether high additional costs are to be expected.

Here is the excerpt from the soil survey:

5. Soil assessment and recommendations
The cohesive loams and loam marl present are settlement-sensitive. A foundation on a statically reinforced base slab is recommended, which can compensate for the potential settlement differences due to the different load application.
The topsoil is to be removed and replaced with a sand bedding made of fill sand, which is to be compacted layer by layer up to 98% of the standard Proctor density.
The foundation of the building can then be carried out on a statically reinforced base slab, for the design of which a bedding modulus of
ks=8 MN/m3
is to be applied.
The base slab is to be equipped with a frost apron.
In the load-bearing areas, a design value of the bearing resistance of
σR,d = 140 kN/m2
should not be exceeded.
Settlements of approximately 1.5-2 cm are to be expected.

Could someone please assist me with this?

Thank you very much

Heiko

Does not sound like drama. Founding on a slab is normal, the topsoil must be removed and compacted subsoil must be installed as well. But just ask the surveyor or your construction partner how they see it

Even the most positive soil report reads like a complete disaster to a layperson We experienced the same. It's normal.

Hi, a brief addition since this is not entirely clear from the question: If you intend to build with a basement, a clayey soil can lead to additional costs because clay is not compactable, meaning the entire excavation must be disposed of and compactable material must be brought in. Furthermore, due to the poor infiltration capacity of clay soil, waterlogging seepage water may occur at times, meaning a waterproof basement may be necessary. As said, only if you want to have a basement. Otherwise, or in general, see Alex’s contribution.

Hi everyone,

long, long ago. Thanks again for your answers. Back then, the plan was to build with Team Massivhaus. The contract was already signed. After we submitted the above-mentioned expert report (we built without a basement), Team Massivhaus informed us that due to the soil conditions, additional costs of around €35,000 would occur. (For a reinforced beam grid with beam cross) This did not match the information from the geologist who prepared the report, a well-known builder, or your statements. We therefore withdrew from the contract with Team Massivhaus and fortunately built in 2018 with local craftsmen.

So always be careful about which extra costs the construction companies try to impose on you.

Best regards Heiko

And that went without a contractual penalty?

Hi Tom,

yes, luckily yes. But it did cost some nerves. Team Massivhaus had assured us that we could withdraw at any time until the planning meeting,
since I had already communicated before signing the contract that I would like to wait for the soil survey. As it often goes, the "nice" salesman persuaded us to sign directly and repeatedly told us that as mentioned above, we could withdraw free of charge until the planning meeting.

At first, they did not want to hear anything about withdrawal. Luckily, two witnesses were present.
We then demanded to build as required in the soil survey (without the additional costs), have the foundation slab constructed by another construction company, or terminate the contract.

It took a while, but Team Massivhaus finally relented and released us from the contract without costs. Interestingly, they then wanted to include a clause in the withdrawal stating that we would not be allowed to build on the property for 5 years. A letter from the lawyer helped and the matter was settled.

That was a lesson for me. On the one hand, not to trust the talk of a salesman and to read the fine print carefully, and on the other hand, to prefer working with local, small businesses.