To limit the probability of inadequate moisture protection, which could lead to an unacceptably high rate of surface corrosion, which could lead to a loss of strength, which could lead to an inability to resist expected gravity loads.
For floors and constructions supporting floors, this is to limit the probability of:
This is to limit the probability of excessive movement, vibration or deflection of floors, which could lead to negative effects on the psychological well-being of persons.