Spalling is the result of the crystallization of soluble salts. In other words the water will dissolve salts from the setting bed and they will crystallize in the pores of the stone causing the spalling. If the floor dries up the spalling could get worse if te salts have not completly crystallized. Chances are they will need to replace the entire floor.
I’m looking for something that I can give to a client so that they can get the approval to redo the floor. Also I have a couple of questions: Will spalling continue to get worse if the flooding has subsided? i.e. what will happen if they don’t replace the tiles. If its half the floor, do they have to replace the whole floor or just the damaged tiles?