We have to replace the controller on our bathtub and we just discovered it is screwed in underneath. So to access it we will have to get a tile person to come out and cut out one of the tiles then we will have to cut through the plywood underneath, change out controller then put everything back together. My question is when you cut a small portion of the plywood out, how do you put it back together. My concern is someone might step on that tile when cleaning the blinds and windows and would hate for the tile to crack if it is not reinforced below.