Minimum thickness of floor slab and cleaning layer

Hello forum members,

is there a minimum thickness for the floor slab of a 1.5-story single-family house without a basement, and what does the "Sauberkeitsschicht" mean and does it always have to be done?
For us, 16 cm was planned—is that too thin?

Whether 16 cm is too thin, I unfortunately cannot tell you. Our base plate is 25 cm thick.

what does the "cleaning layer" mean and does it always have to be done?

**A cleaning layer (or: lean concrete) is a layer of concrete applied on the excavation bottom to create a level, dry, and clean working surface. A cleaning layer is usually executed 5–10 cm thick with unreinforced concrete of low strength class (e.g., C8/10).

The withdrawn DIN 1045-3 required a cleaning layer before the installation of foundation slabs and footings to ensure the necessary accuracy when placing spacers for the reinforcement and thus the required concrete cover. The current European standard DIN EN 13670 does not require a cleaning layer, so there is currently no normative basis for the construction of a cleaning layer. Accordingly, the planner (usually the architect in coordination with the structural engineer) has to decide in which way a level and clean base surface can be ensured that guarantees the necessary cover dimensions during the concreting process.


**Source: BauWissenOnline

For us, 16 cm was planned—is that too thin?

These are typical signs of a low-cost provider; yes—it is quite economical. How much too little it is will be determined by the structural analysis, assuming you chose this provider.

Rhenish greetings

Doesn't it also depend on how much iron was placed in the foundation slab? Ours is, I believe, 22cm, but I have also seen up to almost 30cm. Normally, the structural engineer should know how much is necessary, probably also depending on the layout or the exterior dimensions of the house...