This will be a long question- sorry. I want to install a walk in shower on a solid floor in a very old house. The foul drain runs under where the shower will be (yes it is inside the house) but about 1m away there is an inspection point (also inside the house). The easiest route for the waste water from the shower would be a relatively small channel to the inspection point (by the way it is brick construction) with an entry through the side wall. Is this allowed bearing in mind the property predates any recognisable building regs. (The current system would not be allowed today.) If this would be a solution to the drainage problem are there any tips etc for achieving a good connection.