Can the cleanliness layer be omitted in this construction?

Good day,

I am planning to build a single-family house in the second half of the year, and as a layperson in the construction industry, I will probably have one or two questions over the next few months. It would be really great if I could get some of these questions explained by this community. Thank you very much in advance.

A construction company has offered me the following for the foundation/slab.

- Create fine planning under the foundation
- Excavate the soil for strip footings 45x80cm
- Concrete strip footings with C25-30 including structural reinforcement
- Install dimple membrane under the foundation
- 10cm Jackodur perimeter insulation
- Supply and pour 20cm thick slab including reinforcement

Now to my main question, is the construction of the foundation generally okay, and can a blinding layer be omitted with this setup, or is the blinding layer still absolutely necessary?

Thank you very much in advance for your answers.

Best regards

The cleanliness layer is not required for your structure. However, the "fine planning under the slab" should then be carried out as precisely as possible. When I poured our foundation slab back then, I paid very close attention to ensuring that the entire reinforcement rested on spacers; I would recommend this to you in this case as well. The reinforcement must be covered with concrete by about two fingers' width everywhere, meaning it must not lie directly on the perimeter insulation.

There is generally nothing to criticize about the structure, but the details can only be assessed by a structural engineer. On site, you can ask your foreman for the reinforcement plan – at least then he will realize that you have a certain awareness of the quality of the execution.

That reassures me a lot that there is generally nothing against the structure if it is well executed. Thank you very much for your quick response!

Hello Mephisto23

the cleanliness layer is exactly what it says, a layer so that you don't have to work in the mud. You already have a studded membrane and a styrofoam underlay [Perimeterdämmung]. That is clean enough. And as Knallkörper said: Make sure that the reinforcement has enough distance from the ground. People stomp on the rebar and it can happen that the spacers press into the styrofoam.

Steven

Thank you also for your response. I will definitely be present when pouring the foundation to check the correct position of the spacers/reinforcement.