ᐅ Material for the bedding layer of the patio slabs

Hello,

I am planning to cover the terrace with paving slabs soon.
The mineral concrete base is clear to me, but I am not quite sure what to use on top to create a suitable bedding layer.
Should I use sand or gravel?
Sand might sift into the mineral concrete, be carried away by ants, and water may drain less effectively.
With gravel, the slabs (60x40cm (24x16 inches)) probably won’t lie completely flat.
I would appreciate any advice.

Regards,
Jochen

Split is straightforward. Why shouldn’t they rest properly?

Clearly: crushed stone 2/5.

Use gravel.
The slabs will sit evenly if you tap them again with a rubber mallet.

Crushed stone, a company did it the same way for me.