Design brainstorming, connecting shower and washing machine drain to the same sewer pipe.
My wife asked me to move the washing machine and dryer in the basement. The house is built in 2005 and the basement is not finished.
I attached 2 sketches of what it looks like. Things in black exist already, things in green I plan to install, to make my wife happy .
The builder left an opening in the cement slab where I can see the end of the exiting horizontal drain pipe. It’s 2 inch in dia. and has a plastic cap on it. I cannot be sure where the other end of this plastic pipe goes but judging by the angle it must come from the same vertical drain as the future sink.
As I showed in the first sketch, I’m planning on adding a p-trap to the shower and one to the washing machine (inside the wall, at the back of the shower cabin), then I would go horizontally north and merge the 2 drain pipes somewhere before connecting to the existing drain.
I actually prefer the second sketch. This would ease the installation because I would not need to break too much from the cement slab to pass the pipes. In the second design I connect the washing machine drain pipe to that of the shower using a T so that to avoid using two parallel pipes.
All pipes are 2 inch dia.
Would both these designs work properly? What can I do to make sure the water from the washing machine does not go up in the shower?