Dr. Andreas Leemann:

As Professor Dunlop mentions, moisture is very important in this context. Not all sides of a house would be affected in the same way because the level of moisture changes according to exposure. We cannot say it would take five years for damage to appear because it depends on pyrrhotite content and concrete quality. The blocks have varying concrete quality and they are not all the same. For example, there are the foundations of the houses in Connecticut. Some foundations demonstrated signs of damage after three years, while for others it took 20 years to show those signs. Translating this to Ireland, some foundations might have no problem but others are surely a ticking time bomb. We do not know exactly when it will go off. There is a difference according to pyrrhotite content, concrete quality and exposure conditions.