So I have cut and dug trenches inside my cottage for drainage and WC as per below. I cant find any guidance on depth inside they should be. BS EN 12056-2:2000 only seems to mention outdoor etc. The floor will have 40mm insulation, then 60mm screed on top.
I can go too deep, as I need to get the run to connect to existing Septic tank.
I can go too deep, as I need to get the run to connect to existing Septic tank.