The problem I still see with both of those schematics is that the vent is laying flat after it comes off of the drain line. It needs to be on at least a 45 degree angle from the horizontal to meet code.
I just emailed havasu the doctored schematic. If he can open the attachment and then get it to post on here, I will post some commentary that should be of some help.
Here you go........
Thanks for the assist, havasu.
I am drawing in my recommendations in black.
OK, starting from the left. I am assuming that the vent farthest to the left is the kitchen sink? I drew it in using an combination wye and 1/8 bend fitting that points straight at the vent stack. You can use a wye as you have it drawn, it is just a little easier and uses less pipe to do it like I drew. Turn up into the wall behind the sink, use a sanitary tee to turn out for the drain arm, and vent through roof out of the top of the sanitary tee.
Next in line is the first bathroom group. Once again, a combination wye and 1/8 th bend, than another to send a line off to catch the shower and lavatory. An 1/8th bend to turn toward the toilet, than a closet bend to turn up for the toilet. The side branch for the shower and lavatory will get another combination wye and 1/8th bend for the branch off to the lavatory. Then another 1/8th bend turning towards the shower, and a P-trap for the shower. On the lavatory branch, two more 1/8th bends to turn back towards the lavatory, then turn up for the lavatory and use a sanitary tee in the same way as the kitchen sink, then vent through the roof. The lavatory vent serves the lavatory, the shower, and the toilet. Note that the total length of piping and fittings from the point that the lavatory branches off until the P-trap for the shower can be no more than 6 feet, given that the shower trap is 2". This type of venting arrangement is called wet venting. The vast majority of bathrooms that I have plumbed drainage to in my plumbing career have been installed this way.
Just a short distance upstream, install a wye to tie in a drain line going to the laundry room.
Carrying on to the next bathroom, use another combination wye and 1/8th bend to catch the drain from the toilet, and once again, a closet bend to turn up for the toilet. Another combination wye and 1/8th bend towards the lavatory drain, and once again, the lavatory vents through the roof, and is the vent for the entire bathroom. No more than 6 feet from the lavatory attachment, the trap for the bathtub or shower.
Now we only have the laundry room drain left. The line carries all the way into the wall in the laundry room, and turns up between the washing machine and the laundry sink. That is a laundry sink, correct? A sanitary tee points sideways in the wall for the P-trap for the washing machine box. Then above that is another sanitary tee that points the other direction in the wall, and then a short sweep 1/4 bend turns out for the laundry sink. MAKE SURE that the tee for the washer box is on the bottom, and the tee for the laundry sink on top.
Has this been of help? Do you need to know sizes for the piping?
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