The answer is nothing. Nothing is on the slab. But we have a slab! So that's not nothing.
It's looking a little Guantánamo, isn't it?
Steel soon, I am repeatedly informed. We still haven't figured out what furniture to put in it. Suggestions still welcome.
Me: "How do we prevent people from tagging our wet concrete?"
Our contractor: "Easy. I'm going to sit here with a beer and a baseball bat until it's dry."