I am installing a new kitchen in a room with no services, including drainage. The drainage is required for a sink and adjacent dishwasher. Unfortunately the kitchen installer I have employed does not seem to know about this part of the job, so I am trying to work it out. The floor will be tiled, so everything below it has to be right.
I am thinking that the dishwasher drain will attach to the sink trap and a 40mm pipe drop straight down through the floor into the void below the floorboards, solvent fixed to a 120 degree bend and 40mm pipe out though the wall at the lowest point just above the concrete plate. Once outside the 40mm pipe will join a socketed square hopper. The hopper will be joined to a 'p' trap gully via a piece of 110mm pipe with a socket or double socket. The 110mm outflow from the 'p' trap will run about 4 meters to join an existing 110mm drainage pipe via a 'y' 45 degree junction. I want to use a three socket one but not sure if it is possible to fit one of these effectively into an existing fixed pipe run? Perhaps I need to lose one of the sockets and use a rubber sleeve with jubilee clips to join?
Any comments on this or the general drainage plan much appreciated.