Inspection shaft on property full

Key data are still missing,
- Is your house 2m above or below the street,
- How was the precast concrete basement sealed, black or white tank, or just with a coating
- How was the transition from the floor slab to the basement walls sealed,
- Is it waterproof concrete
- what diameter does your drain pipe to the sewer have

The property is about 2m above the street.

The exterior basement walls were sealed with a fully glued waterproofing membrane (instead of bitumen), extending down past the floor slab. Thick Styrodur panels were applied on top. Then a studded membrane. New drainage pipe with correct slope. An experienced civil engineer from our family did all this. However, this has not yet been laid all around the house, currently only at the back and a bit around the corner. The front side, where the inspection chamber is, has not been done yet.

I do not know the diameter; unfortunately, it is not indicated on the plans I have. Only the drainage is 100mm, that is stated there.

Unfortunately, I also cannot say which concrete was used in 1979. No idea if WU concrete even existed at that time.

Which concrete was used in 1979, I unfortunately cannot say either. No idea if WU concrete even existed back then.

It has existed for much longer. Modern norms/standards, however, only since the 90s. Assume that it is not modern WU concrete (if anything in that direction was built at all).

This was done by an experienced civil engineer from our family.

Then he should also advise you now on solving the water problem. He knows the conditions in and around the house. Experience shows that water in the basement usually comes from rain over the roof and downpipes, from the property's own drainage system, or from an undersized drain during heavy rain.

Unfortunately, this person no longer exists... I also do not assume any WU concrete, as that would presumably be noted somewhere in the documents. Thank you for the assessment , that somehow currently matches my suspicion as well.

I also do not assume any WU concrete,

Then the water could also push through the base slab. A professional is needed for that. No further help can be given from a distance.