Hello,
In the soil report I had done last year, it states that no groundwater was found up to a drilling depth of 4 meters (13 feet). This is not surprising since the groundwater level is below 6 meters (20 feet) in our area. The report also says that I can install a drainage system around the basement. This was also offered to me with the prefabricated basement. My neighbor did exactly the same and directed the drainage water into an infiltration well. The soil here is sandy.
Now, my excavation contractor came for a discussion and said that drainage is risky—especially since I have to allow surface water to infiltrate (a gravel infiltration trench is also not far from the house) and that all the water would then run into the basement pit. A water damage to the basement would be inevitable. He recommends sealing the basement with a waterproof tank system. That would cost me an additional 10,000 euros. He suggested I ask my soil expert how the drainage water should actually be infiltrated on-site and whether he would sign off on it. Of course, he obviously won’t do that. The contractor said he will put his concerns in writing and likely will not provide any warranty in case of problems.
Now I am extremely uncertain about what to do.
In the soil report I had done last year, it states that no groundwater was found up to a drilling depth of 4 meters (13 feet). This is not surprising since the groundwater level is below 6 meters (20 feet) in our area. The report also says that I can install a drainage system around the basement. This was also offered to me with the prefabricated basement. My neighbor did exactly the same and directed the drainage water into an infiltration well. The soil here is sandy.
Now, my excavation contractor came for a discussion and said that drainage is risky—especially since I have to allow surface water to infiltrate (a gravel infiltration trench is also not far from the house) and that all the water would then run into the basement pit. A water damage to the basement would be inevitable. He recommends sealing the basement with a waterproof tank system. That would cost me an additional 10,000 euros. He suggested I ask my soil expert how the drainage water should actually be infiltrated on-site and whether he would sign off on it. Of course, he obviously won’t do that. The contractor said he will put his concerns in writing and likely will not provide any warranty in case of problems.
Now I am extremely uncertain about what to do.
Hausner schrieb:
everything flows into the house foundation pit. Water damage to the basement would be inevitable.Once the basement is built, the ground is filled in with backfill soil, which is looser than natural soil, so your excavation contractor is correct. You wouldn’t be the first to cause building damage with your own roof drainage system because it is too tight and collects too much rainwater. The water doesn’t suddenly seep down 6 meters (20 feet); instead, it backs up.H
hanghaus20001 May 2021 10:57If then not or but and.
Nida35a schrieb:
will be filled with soil, which is looser than natural groundIt should not be filled with soil but rather backfilled with lean concrete.tomtom79 schrieb:
It should not be backfilled with soil, but should be filled with lean concrete.Unfortunately, it is often backfilled with the excavated soil that is still heaped nearby.Similar topics