We used what they call rock-crete around here.  It's limestone that hardens after it's settled and dry.  I don't know what screening are?

We are putting down mats this year though, because after a time, the top layer can loosen and creates some dents and holes, especially where they potty.

When I posted this I totally forgot bout my friends stalls that she had done that I helped her with!  It was around 200-250 for ea 12x12 stall and it was easy to install tho it took us girls awhile!  She ordered the stall skins.  There is another called stall savers.  not sure if same material but installed the same.  She had hers a long time and they did save shavings and easy to clean! and never had holes!  So I will be doing this!  I'm writing it down! lol  I can be so forgetful!