Verified answer

6 cubic yards should be enough, but in my experience I always seem to come up short (I highly suspect they deliver less than what I actually order, but I can't prove it). Also, I" isn't very thick, are you sure that's going to be enough? I'd go at least 1-1/2", and that way you can use standard 2 X 4's to screed it. 1" would require 9 yards, by the way.