I want to fit a toilet under the the stairs and do not want to use a saniflow. To put a standard soil pipe in I need to cut the kitchen floor up, by the time I have angle 1/4" in every 1ft the pipe will be bellow the damp course. I don't mind pulling up the block paving and lowering the existing outside soil pipe (this is from the existing downstairs toilet tat is coming out), I am just not sure about exiting the house with a pipe under the damp course and concrete floor?
