Hi all. Noob here. First, thanks for the amazing resource, I've found it super useful in my research, along with the code book.

From that research I designed the attached plumbing diagram. For context, this is an existing basement laundry room (washer and sink) that shares a wall (and plumbing) with a basement bathroom.

I'm looking for confirmation and any feedback on the diagram. The reasoning behind my designs are as follows;

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1) Laundry room washer drain: Because the bathroom toilet drains into the secondary (basement) mains drain I cannot, apparently, drain the washer into it, due to siphoning concerns with the toilet p-trap, as I could only tie it in above the toilet drain tie-in since the toilet drain tie-in is below ground. Therefore the washer is designed to take a 90 degree turn (shown is a circle in the diagram as it would be travelling perpendicular to the plain of the paper) around the secondary (basement) mains drain and tie into the original 4" cast iron drain pipe that is used for draining the main floor bathroom fixtures (toilet, tub/shower, and sink).

Question: Can washer drain pipes turn a 90 degree corner?
Question: Anything else to consider/wrong with this plan for the washer drain?

2) Laundry room sink drain: This is separate drainpipe to the washer and will tie in to the secondary (basement) main drain.

Question: Does this need a clean out?

3) Laundry room washer vent: Either an AAV 6" above FLR (Flood Level Rim) OR connect it to what I think is a Future Vent (if it is operational).

Question: How is best to check operational viability of a future vent?
Question: What size AAV is needed for a 2" drain pipe venting one fixture?

4) Laundry room sink vent: Tie in to secondary (basement) mains drain 6" above FLR. THis is where all the other fixtures in the basement bathroom (sink and tub/shower) are tied in to OR connect to Future Vent if I go with AAV for washer venting.

Question: None

Further details shown on diagram:
a) 2" ABS pipe for washer drain (including p-trap) and sink drain (except p-trap which is 1.5"
b) 2" ABS pipe for washer standpipe (18-30" length)
c) 2" ABS pipe for washer p-trap weir (6-18" off ground)
d) 1.5" ABS pipe for washer and sink vent (no more than 1/3 on the horizontal. No dips/sags)
e) tbd AAV size located 6" above FLR
f) PVC wye with rubberized sleeves and clamps to tie washer drain into cast iron drain
g) 1/2" pex pipeing for supply lines



Edited 2 times.

awfully hard to get a clear picture of the piping layout.
i can tell you from what i see you are way off base.
the AAV is useless for a wash mach drain.

It passed inspection this morning. AAV wasn't needed.