Hi I will be ripping a bath with shower out and want to replace with a wetroom, I want to keep a level floor throughout the bathroom I am not wanting to buy a tray and plan to make one out of plywood I know this can be done if ranked correctly. I am just wanting to know how to get the slopes right and how to set out the timber to carry the weight and not have any movement once completed. I have searched a lot about this and can’t seem to find much apart from cutting the joists down is a good idea. Any help to at all or links to other threads on this is appreciated.