Aav distance from toilet - will it flush well?

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Homewonder

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Hi all,

Check out the photo - Here’s what’s been installed. The vanity is on the top right with AAV installed above the waterline. The shower drain (out of frame) on the bottom left T’s into the vanity drain line which then T’s with the WC and everything drains out to the left. The distance between that last T and WC flange is 5 feet.

My concern is lack of airflow “behind” the flush. Technically this is to code, but I just wanted to ask before installing the floor. Should I “T” in the vanity/vent line closer to the WC?
 

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Twowaxhack

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It’ll work like it is.

I would’ve like to see the lavatory connect to the toilet arm and the vent go through the roof.
 

Homewonder

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Can’t vent outside unfortunately. But I’m considering rejigging to a more linear design if the consensus says the current WC won’t have enough oomph. In that case should the bottom of the WC stub utilize a Y-T to direct flow to the left? What’s the right way to do this.
 

arctic bill

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I would like the y before the toilet y. this way the wet vent protects the toilet. Let us say that someone ran the sink full on for a while it could syphon out the toilet . I always like a toilet at the end of the line .
 

Twowaxhack

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I would like the y before the toilet y. this way the wet vent protects the toilet. Let us say that someone ran the sink full on for a while it could syphon out the toilet . I always like a toilet at the end of the line .
A lav will never flow enough to siphon a toilet. Especially with a toot vent upstream. Even when filled and released all at once.

It will open the vent and suck air there instead of the toilet.

Either position it will protect the toilet ( not needed because of the low flow from the lavatory ).
 

Homewonder

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Ok - thank you. Last question.

If I tie in the 2” lav line with a Wye just past the toilet riser, should I cut and cap the original lav line where it links up with the shower? Or is having the two parallel lines no issue? Hope that makes sense! Basically the venting would be meeting the 3” pipe at two places. One near the toilet and again about 5’ down the line.
 

Homewonder

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Technically not unused, just duplicate. It would be an AAV access for the shower. But if I did remove it, the shower would still have vent access via the 3”. See photo. Red is the new WC aav access. Green length is the proposed leave/remove section.
 

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Twowaxhack

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The shower has to be vented. If your AAV at the lavatory is serving the shower then leave the piping alone.

You reallly need to vent the shower with a vent out the roof or another AAV if the shower isn’t vented
 
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