To limit the probability of an inadequate substrate, which could lead to discontinuity in the waterproofing, which could lead to the ingress of moisture from the ground, including water that is under hydrostatic pressure, which could lead to deterioration, which could lead to compromised structural integrity of elements protected by such walls, which could lead to harm to persons.
To expand the application of Subsection 9.20.3. to include parging on masonry below ground that is applied as a substrate for waterproofing.