We are not builders/experts we are meerly showigng what we did. 

When the screed was being poured in the showers we boxed off where the showers were going as we have wet rooms and needed the floors to slope. 
Ciaran measured the floors and laid the guides on a slope. Once they were stuck in place he placed cement under them to keep them in place. He then filled in the whole shower floor, leveling as he went along so that there was a nice slope on the whole floor all the way to the drain.