To limit the probability of excessive moisture loading, including hydrostatic pressure, on foundation walls and basement floors.
This is to limit the probability of water ingress, which could lead to:
This is to limit the probability of:
To limit the probability of excessive moisture loading on the soil immediately beneath the footings, which could lead to saturation and a reduction in the soil's bearing pressure, which could lead to compromised integrity of supporting soils, which could lead to failure of the foundation, which could lead to damage to the building.