Mr. Noel Carroll:

It is very likely, given that these quarries have existed since time immemorial, some similar type of stone got in under older houses. In those cases there were different construction methods. At the time many people had timber floors. There might not have been the same degree if compaction as there was previously. The bottom line is if one does not have the damage one does not have the problem. There could be pyrite and it might even have expanded a little but if it did not push up the floor, one would not go looking for it. In truth there was no problem prior to the mid to late 90s in this area. It is quite clear again from the pyrite panel report that it was the expansion in terms of the amount of stone being produced in quarries that prompted this problem to occur.

It would appear that people started using quarries that might have been marginal or not considered suitable before they started producing this stone, production of which increased from 30 million tonnes annually to 130 million tonnes annually. That is probably the genesis of the problem.