To limit the probability of an inadequate thickness or inadequate lateral support for concrete or unit masonry foundation walls, which could lead to an inability to support vertical building loads or lateral earth loads, which could lead to damage to the foundation or the superstructure.
This is to limit the probability of:
For floors and elements supporting floors, this is to limit the probability of excessive deflection, which could lead to persons tripping or falling, which could lead to harm to persons.