Thanks Fig and Duraleigh. I'm just trying to get this straight. Basically, I'm going to cut my flagstone so that the deck-side of the stone is fairly even with the back of the beam all the way around the pool. Then I add poly-void to the back and grout on the top. Then install my decking.
Does anything change because the deck is dry-set and will not be on a concrete base and also not mortared or grouted in?

Brad
Waterworks