[Clause (a)] To exempt certain designs from the application of the waterproofing requirements of Sentences 5.8.2.2.(2) to (5), on the basis that the designs employ defined alternate methods of controlling the potential for moisture ingress.
[Clause (b)] To expand the application of Sentence 5.8.2.2.(2) to allow the use of dampproofing materials for designs that employ defined alternate methods of controlling the potential for moisture ingress.