ᐅ Question about Frost Protection for Concrete Foundations of Garden Sheds

Hello everyone,

I am currently working on the foundation for our Biohort garden shed.
I would like to create it as a concrete slab foundation.

Now I am considering what base layer to use under the concrete.
I still have 16/32mm (0.6-1.25 inch) rolled gravel left over—is this suitable for under the foundation?
Of course, it can’t be properly compacted, but as a moisture barrier, it should be excellent, right?

On top of that, the formwork, separated by a PE (polyethylene) sheet.

What do you think?

Thanks for your advice!

I think point foundations made of concrete would be sufficient for the small house.
Roller gravel is probably not a good idea; how is that supposed to hold?
Usually, crushed stone is used.
However, if you make your point foundations deep enough, you don’t even need a substructure.