Ok !
I’m nearing the point I need to start planning and doing this .
I’ve deliberately left gaps in my screed for a flush with finished floor shower .
My assumption was to treat the bathroom like a wet room I.e water proof it to the same level even though it’s not a wet room . Currently don’t know the shower enclosure we will have but assume it will just be a glass panel from floor up to ceiling . One question is how do these attach to the floor ? - some special slot fixing that g
Maybe these if you need to extend the pipe without making the slab/beam hole too much bigger:
Geberit 366.887.16.1 Hdpe Straight Connector
£21.48
Tax included
Geberit 366.887.16.1 HDPE Straight Connector
90mm - 90mm
Ring seal socket
Or
Geberit 367.887.16.1 Hdpe Straight Connector
£21.48
Tax included
Geberit 367.887.16.1 HD