"Scribe in, water proofing as per client requirement". The client & Builder do not want this design at all, causes nothing but trouble and truly looks horrible. If you push the parapet flashing up against the top wall girt, cut the internal wall sheet and push up to the bottom of the parapet flashing and then add another wall girt to fix the bottom cladding to, this will fix any water proofing issues and we wont need to try justify the design to our customers after its constructed.