Hi, probably too late to comment now as you've already gone with someone on this project. Along the wall is the most common solution as it is easier to create falls, particularly if you have large format tiles. You will get water out of the shower given this is a just a freestanding panel, and it will also be cold in winter (speaking from experience) without a door on it. In the Australian Standards you are required to have a 'water stop' or step down to at least 5mm - most people don't do this and this is where problems can start from a waterproofing point of view. Good luck - hope it goes well

I have done exactly that. 600x600 on the entire top floor including the out side area and the bathroom. The outside stairs and the front porch are exposed to the weather so I have a more textured non slip version of the same tile. Very happy with the my choice.

Have been double waterproofing for many years and NEVER had a bathroom leak Have renovated many 100 yr old bathrooms 1..... Remove floorboards, check dimensions ,spacing and condition of bearers and joists and if level...More often than not 100 yr old homes do not meet 2020 Standards And all supporting timbers require replacement ( Not a big job, worth the effort ) 2....Plumber should check drainage, moving items easy and cheaper at this stage 2 ....Lower if necessary to level timbers and Scyon to finish 40 mm lower than outside floor, fix to manufacturers spec 3... Plumber to fit item pipes and drainage penetrations ( Puddle Flange ) consider location of floor waste ...may be preferable under vanity drainage for shower and floor waste.. 4....Waterproof entire floor, up walls 300mm shower etc to standards Prime and we use Davco K10 plus, 5... Add water bars to shower and doorway, Sikaflex , adhesive/sealant ( NEVER Silicane ) ALL Walls to floor.' Shower corners to 2000 mm Waterproof second coat 6...Tiler to lay tile bed and establish fall to floor and shower 7.. After drying, Polyester bandage shower walls to floor, Waterproof Third Coat 8... Final Coat of waterproofing 9...Tiler to tile Ii takes around 7 days to waterproof as for $ 50,000 bathrooms Any further questions, Pleas feel free,If in Sydney Contact

Your concretor is never going to fix the problem he has created to your satisfaction and to an appropriate and professional standard of his own free will to remedy his laziness. I am assuming that he has been fully paid for his shoddy work. I wouldn't allow him (or his plumbing mate) anywhere near my property again. I would be paying my own plumber the $4500 to fix it, or get a few more quotes from some other plumbers - sometimes a clever plumber can work out a cost-effective workaround. Then speak to your lawyers to write some aggressive letters demanding compensation, but there is no guarantee that you will get what you are owed. Without knowing how big the slab is $2200 seems very cheap for the amount of work, bobcat hire and materials needed, and perhaps should have rung alarm bells about you get what you pay for. I would also be keeping the QBBC informed as this scam artist is giving registered tradesmen a bad name. Best of luck, and sorry for your bad experience Dr Retro of Dr Retro House Calls and Dr Retro Virtual Visits via Zoom.