My pool is a steel frame and after a full renovation we decided to go with a thermal edge bluestone coping for a more modern and clean look. The pool was built in the 90’s and so the walls aren’t perfectly straight. I had the PB put a 4ft rough concrete pour around the pool which will carry the pavers afterwards. So this week they came back and added the mortar, wire mesh, and mortar again before placing the bluestone in place. It looks great in my opinion; however, once inside the pool, you can see the small gaps beneath the stone and the steel edge of the pool. Anyone have any recommendations on what to fill this in with, if anything? I feel like it may be normal since the mortar doesn’t adhere to the flat too of the steel walls.