Hi there,
I'm based in SA and I've just demolished my ensuite (which for reference is very small, 3m x 1m). Plumber has been in to chase the walls and move some of the plumbing and now it's onto preparing the walls for waterproofing. I'll be waterproofing myself (which I'm fully aware you may not all agree with), so I just want some advice on preparation of these walls before waterproofing. I'm hesitant to go with Villaboard as I'll lose approx 20mm per wall between the furring channels and the sheet in an already small space, so leaning towards rendering/plastering.
What do I need to do specifically for patching the chase work (which at it's deepest points is up to 70mm), and also to smooth the rest of the walls (the render that remains seems really sturdy and no drummy spots)?

Shower pipework
Vanity pipework