Sagging concrete floor

[kiao]

Hello!

I've recently hired a company to renovate a basement room: excavation, macadam, foam insulation, reinforcement, water-based underfloor heating, and on top 10 cm of concrete.

A week after the floor was completed, we noticed it sounds hollow when you walk on it. The floor vibrates when you walk. It is not completely solid as we had expected.

We are considering bringing in an inspector, but it's expensive, so I thought I'd ask here first.

Is the floor defective?

What I know about the construction is that the concrete is hand-mixed fine concrete and it has not been vibrated. The macadam is also not packed.

Does anyone have knowledge about this?

 

[Mats-S]

Is the floor defective?

Yes!

Of course, a concrete slab should not vibrate; then the foundation is improperly done. I assume the concrete has reinforcement and underfloor heating embedded in it (?)

One might speculate that the crushed stone is so uneven that the foam insulation does not lie flush with the substrate, and therefore the foam can move when loaded.

Get an inspector there; he will probably say: Do it again, Do it Right!

 

[kiao]

Yes!

Of course, a concrete slab should not vibrate; the groundwork is done incorrectly if it does. Because I assume the reinforcement and waterborne underfloor heating are embedded in the concrete(?)

It can be speculated that the macadam is so uneven that the foam insulation is not flush with the ground, causing the foam to move when loaded.

Bring in an inspector, he will likely say: Do it over, Do it Right!

Yes, the reinforcement and underfloor heating are in the concrete. Thank you very much for your response!

 

[Nilc]

What happened here? Was there something wrong with the concrete slab? Curious

 

[kiao]

What happened here? Was there something wrong with the concrete slab? Curious

The inspector determined that the floor was okay. According to the law, the fault must be proportionate to the required measures. He said that the floor sounded hollow and maybe wasn't completely solid but that it wasn't yielding.
He suspected that it was thinner than 10 cm, but we drilled a test hole and it was about 10 cm.
However, other faults were found in the construction, but not in the floor...

 

[Nilc]

Oh okay. I have the same experience with my floor. But then it's probably not a problem

 

[M85]

Out of curiosity, how much does this type of work cost nowadays for a room in a basement? (I have an old basement that's starting to be due...)

 

[kiao]

The room is about 7 square meters and both the floor and walls cost about 106,000 before ROT.