I've had a builder check on the formworks, etc, before the slab was poured. He advised me to parge (do pargetting ) the exposed slab's edge, with something called "Master Black" or "Black Jack". I couldn't find any reference to the stuff, only to something called Poly-Wall Pro 1000 dam-proofing.
What I'm after is something I could apply to the exposed 75mm of slab edge, without invalidating its termite-protection function.
Chris