Waterproofing regulations in Victoria

Hi, to save me the costs of purchasing the regulation guide. Can anyone help with a DIY waterproofing job to repair a leaking shower?

To save costs, thinking of ripping out existing tile (concrete base) and a ways up the walls for waterproofing as opposed to removing the whole shower.

Question:
1. does Vic regulations require waterproofing work to be carried out by a licensed tradesperson as in other states?
2. if not, do I need to waterproof up the whole walls or is partial around the corners sufficient to meet regulations?

Thanks!