Thank you Hugh, glad to hear. I'm a total noob!
The shower will be accessed from the room with the higher floor luckily, so will be floor level. That would be a heck of a step otherwise!
Will try to remember to put a flap for gaining access to the pipes from the side once the tray has been...
Apologies if already covered but I couldn't find a post that described my objective:
Picture hopefully describes it most clearly. I want remove my S-trap pan, put in a p-trap and add a shower on my ground floor bathroom. The main soil stack is not accessible so wanting to join the shower waste...