Detailing stoop slab: concrete to wood #green
I am building a new house which will be clad in full-thickness natural stone veneer. A stoop slab just outside the front door will be poured on top of a cold room that's part of the foundation. My concrete contractor, of course, wants to pour the slab right against the rim joist. That's not going to happen. But what SHOULD happen? With the masonry veneer, the wall above includes a 1" air space--should I have the guy leave the 1" also between the slab and the rim? How would I ensure proper water drainage out of that space? Or perhaps should I just put in a triple layer of 6-mil plastic against the rim and let him pour up to it, then silicone the intersection?