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Help with new Kitchen drainage please

Postby rhino666 » Sun Mar 19, 2023 11:27 pm

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.
rhino666
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Postby stoneyboy » Mon Mar 20, 2023 10:13 pm

Hi rhino666,
You’ll probably need to use a 90 bend in place of the 120.
It’s probably worth fitting a mini inspection chamber with sliding collars for the final connection.
Regards S
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Postby rhino666 » Tue Mar 21, 2023 5:53 pm

Thank you stoneyboy, appreciate your reply.
Yes, agreed a 92.5 degree bend will facilitate flow as well as accommodate solvent fixing to the hopper.
Now here is my remaining dilemma, considering the tiled floor going down, which once down I NEVER want to touch again. Do I go through the floor and out of the house direct to the hopper with all waste pipe hidden but if a problem, will be a real issue............or do I chicken out, as most seem to and go out of the house above the floor level, with an unsightly pipe dropping on to the hopper grid?
rhino666
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Postby stoneyboy » Fri Mar 24, 2023 10:59 pm

Hi rihno666,
Do the underfloor option using a continuous length of pipe - support it at regular intervals.
If it creates problems in the future you could bypass it with the exposed pipe option.
Regards S
stoneyboy
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Posts: 6319
Joined: Wed Dec 10, 2008 6:44 pm



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