OSB and drywall directly on the slab?

[KingHippo]

Is it okay for OSB and gypsum to be directly against the slab, or should you have capillary-breaking plastic underneath just like for the sole plate?

 

[injonil]

It is common to let the boards stop a few mm above the slab, for example using masonite pieces as spacers. As you say, it is not good if the boards have contact with the slab.