Sidline Tile -replacing

I have a concrete pool that needs sidline tile repalced.  Before I put my tile on I need to build up behind the tile to make a smooth surface.  What product should i use for this?  also what adhesive should i use for my Tile?

Hi PatRoe,

Unfortunately we do not have too much experience with tile. I would suggest reaching out to this company TileXpressions - Team Horner