DWV help me make it right! (CAD renderings included)

hj said:

Why are those two vents going over to the lateral line and then jumping up into it, rather than just going flat into the side of it?

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Because there is a joist in the way and not enough clearance behind that joist (the foundation wall is in the way) to fit the plumbing. I took the most direct route I could. I can drop the lateral vent down the wall to facilitate a flat connection from the two drain vents. I guess it would save 2 90 bends.

The vent from the downstairs may have to be rerouted to the left side of the main vent to get out from under the window

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It can't be. The cabinet to the left of the sink is a drawered unit with no clearance behind it and the only path to the basement is 6" outside the finished wall.

It CANNOT be run the way you show it unless the BOTTOM of the pipe is at least 36" above the floor, NOT 30". This is not negotiable.

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I am stuck between a rock and hard place here. I hate to use an AAV, but It is looking like the only reasonable alternative other than a spaghetti mess of plumbing back and forth to get the main vent to the basement and a vent or loop vent for the kitchen sink. Is a spaghetti mess preferred to an AAV?

I do appriciate the help... it is very important to me to get this as right as possible.

Okay... I hope this iterative process is getting somewhere.

I have attempted to follow rules I read in another thread here. I have no choice but to go horizontal with the vent, but I can't move the drain, it MUST stay in the cabinet floor, as does the vent extension into the basement.

I have taken the vent off of the drain in a horizontal out into the stud space beside the window and tied it into the vertical vent at least 6" above the counter height. The sink is the highest fixture draining or vented.

I think I have corrected all of the errors, eve if it is somewhat odd... the odd framing in this house is hard to work around.

Top image is the revised kitchen plumbing showing framing. Bottom image is all plumbing showing foundation only.






Thoughts?

mess

quote; Is a spaghetti mess preferred to an AAV?

Read some of the postings from people who have AAV's that do not allow the sink to drain, because there is a stoppage SOMEWHERE ELSE in the system and then decide which is best. WIthout being there we cannot tell whether it actually takes a "mess" of piping to do the job correctly. That last one is much better, as long as the connection back into the riser is at least 36" high, and preferably 42". My next revision, assuming there is enough depth, would be to lower the horizontal 4" to the point where the combo's or Y's could be facing upwards with street tees into them for the trap arms to eliminate those quirky "U" turns in the vents. There is nothing WRONG with them, they just look odd.

The trap under the window...have the trap arm go into the wall and 90 left through the studs and hit the T in the wall and the vent going strait up to meet the other vent lines and the waste line going down then nothing will be flat vented...

When moving out of a wall and continuing down try and use 45s if you can instead of 90s

Cass said:

The trap under the window...have the trap arm go into the wall and 90 left through the studs and hit the T in the wall and the vent going strait up to meet the other vent lines and the waste line going down then nothing will be flat vented...

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I would love to do that, but I can't bring the drain back out of the wall any further to the left. The only path to the basement is through the cabinet floor and the cabinet to the left is a drawered unit. To the right of the sink cabinet is the dishwasher. So the only way down is where it is at now

So do it and bring the waste line back into and under the cabinet.

hj said:

quote; Is a spaghetti mess preferred to an AAV?

That last one is much better, as long as the connection back into the riser is at least 36" high, and preferably 42".

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Yes it is at least 42"

My next revision, assuming there is enough depth, would be to lower the horizontal 4" to the point where the combo's or Y's could be facing upwards with street tees into them for the trap arms to eliminate those quirky "U" turns in the vents. There is nothing WRONG with them, they just look odd.

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I will certainly keep that in mind and will see how much room I have to work with.

Before anybody asks...
The horizontal waste pipe can not be burried under the slab becuase the foundation is very irregular and comes out 1' or so from the wall in places. Nothing about this entire project has been easy or ideal.

Cass said:

So do it and bring the waste line back into and under the cabinet.

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I would have thought the straight drop for the waste line and a wonky vent would have been prefered to a straight vent and a wonky waste line

Have I mentioned the trapless unvented add-on bathroom yet? That is the next project

You can snake a waste line but vents normaly are not easily accessable...