ᐅ Excerpt from Geotechnical Report: Soil Assessment and Recommendations
Created on: 19 Nov 2017 14:35
H
Heiko123Hello everyone,
I am new here and currently planning the construction of a semi-detached house in Lower Saxony. For this, I had a soil survey carried out on my property. Unfortunately, I cannot determine from the report whether to expect significant additional costs.
Here is the excerpt from the soil report:
5. Soil Assessment and Recommendations
The silt and silty clay layers present are sensitive to settlement. A foundation on a reinforced concrete slab is recommended, which can compensate for potential differential settlements due to varying load distribution.
The topsoil must be removed and replaced with a sand bedding made of fill sand, which should be compacted in layers to 98% of the standard Proctor density.
The building foundation can then be placed on a reinforced concrete slab designed using a subgrade modulus of
Calcium silicate brick = 8 MN/m³ (MegaNewtons per cubic meter).
The slab must be equipped with a frost protection edge.
In load-bearing areas, the design bearing pressure should not exceed
σR,d = 140 kN/m² (kiloNewtons per square meter).
Settlements of approximately 1.5–2 cm (0.6–0.8 inches) are to be expected.
Could someone please help me understand this?
Thank you
Heiko
I am new here and currently planning the construction of a semi-detached house in Lower Saxony. For this, I had a soil survey carried out on my property. Unfortunately, I cannot determine from the report whether to expect significant additional costs.
Here is the excerpt from the soil report:
5. Soil Assessment and Recommendations
The silt and silty clay layers present are sensitive to settlement. A foundation on a reinforced concrete slab is recommended, which can compensate for potential differential settlements due to varying load distribution.
The topsoil must be removed and replaced with a sand bedding made of fill sand, which should be compacted in layers to 98% of the standard Proctor density.
The building foundation can then be placed on a reinforced concrete slab designed using a subgrade modulus of
Calcium silicate brick = 8 MN/m³ (MegaNewtons per cubic meter).
The slab must be equipped with a frost protection edge.
In load-bearing areas, the design bearing pressure should not exceed
σR,d = 140 kN/m² (kiloNewtons per square meter).
Settlements of approximately 1.5–2 cm (0.6–0.8 inches) are to be expected.
Could someone please help me understand this?
Thank you
Heiko
Doesn’t sound like a big issue. A foundation on a concrete slab is normal, and it’s also standard that the topsoil needs to be removed and a compacted subbase installed. But just ask the inspector or your building partner how they see it.
Even the most positive soil report can read like a complete disaster to a layperson. We experienced the same. It’s normal.
Even the most positive soil report can read like a complete disaster to a layperson. We experienced the same. It’s normal.
Hi, a brief addition since this wasn’t entirely clear from the question: If you plan to build with a basement, clay soil can lead to additional costs because clay is not suitable for compaction. This means the entire excavation must be removed and replaced with compactable material. Furthermore, due to the poor infiltration capacity of clay soil, temporary buildup of seepage water may occur, which would require a waterproof basement. As mentioned, this only applies if you want to build a basement. Otherwise, or in general, see Alex’s post.
Hi everyone,
It’s been a long time. Thanks again for your responses. Back then, the plan was to build with Team Massivhaus. The contract had already been signed.
After we submitted the aforementioned report (we built without a basement), Team Massivhaus informed us that, due to the soil conditions, there would be additional costs of around €35,000 (about $38,000) for a reinforced beam grid with cross beams. This did not match the information from the geologist who prepared the report, a well-known builder, or your statements.
For this reason, we withdrew from the contract with Team Massivhaus and were fortunate to build in 2018 with local tradespeople.
So always be careful about which extra costs construction companies try to charge you.
Best regards,
Heiko
It’s been a long time. Thanks again for your responses. Back then, the plan was to build with Team Massivhaus. The contract had already been signed.
After we submitted the aforementioned report (we built without a basement), Team Massivhaus informed us that, due to the soil conditions, there would be additional costs of around €35,000 (about $38,000) for a reinforced beam grid with cross beams. This did not match the information from the geologist who prepared the report, a well-known builder, or your statements.
For this reason, we withdrew from the contract with Team Massivhaus and were fortunate to build in 2018 with local tradespeople.
So always be careful about which extra costs construction companies try to charge you.
Best regards,
Heiko
Hi Tom,
Yes, luckily so. But it did cost us quite a few nerves. The Team Massivhaus assured us that we could withdraw at any time before the planning meeting, since I had already mentioned before signing the contract that I wanted to wait for the soil report. As it often happens, the "friendly" salesperson persuaded us to sign immediately and repeatedly assured us that, as mentioned, we could cancel free of charge up until the planning meeting.
Of course, when we tried to withdraw, they initially didn’t want to honor that. Fortunately, two witnesses were present. So we demanded that they build according to the soil report (excluding additional costs), have the foundation slab constructed by another company, or cancel the contract.
It took a while, but Team Massivhaus eventually backed down and released us from the contract without fees. Interestingly, they then wanted to include a clause in the cancellation stating that we would not be allowed to build on the land for five years. A letter from a lawyer helped, and the matter was settled.
This was a lesson for me. First, don’t trust a salesperson’s talk and always read the fine print carefully. Second, it’s better to work with local, smaller companies.
Yes, luckily so. But it did cost us quite a few nerves. The Team Massivhaus assured us that we could withdraw at any time before the planning meeting, since I had already mentioned before signing the contract that I wanted to wait for the soil report. As it often happens, the "friendly" salesperson persuaded us to sign immediately and repeatedly assured us that, as mentioned, we could cancel free of charge up until the planning meeting.
Of course, when we tried to withdraw, they initially didn’t want to honor that. Fortunately, two witnesses were present. So we demanded that they build according to the soil report (excluding additional costs), have the foundation slab constructed by another company, or cancel the contract.
It took a while, but Team Massivhaus eventually backed down and released us from the contract without fees. Interestingly, they then wanted to include a clause in the cancellation stating that we would not be allowed to build on the land for five years. A letter from a lawyer helped, and the matter was settled.
This was a lesson for me. First, don’t trust a salesperson’s talk and always read the fine print carefully. Second, it’s better to work with local, smaller companies.
Similar topics