Island vent and other questions

[Pulse]

The vent will run along the joists a couple feet, run up a wall, then into the attic. That 1.5” vent is planned to handle the laundry and kitchen sink, as seen. It will also most likely pick up a floor drain and an unused condensate drain before going up the wall. Is the 1.5” pipe sizing and everything else ok?

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I would also like to know if back to back toilets can be fed off of a single 1/2" pex line.

 

[Tuttles Revenge]

The vent from below must connect no lower than 6 inches above the flood level of the upper floor fixture. So the island loop vent should have a Foot vent that vents to atmosphere / ties into other vents. In the below diagram, your vent from the laundry below could tie in at the point above where the diagram points to Wall.

A tad bit of research indicates that Pennsylvania allows Air Admittance Valves to be used in lieu of loop vents. But that may not be true in your individual jurisdiction.

Chapter 31: Vents, Pennsylvania Residential Code 2009 | UpCodes

UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction

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[Pulse]

The vent from below must connect no lower than 6 inches above the flood level of the upper floor fixture. So the island loop vent should have a Foot vent that vents to atmosphere / ties into other vents. In the below diagram, your vent from the laundry below could tie in at the point above where the diagram points to Wall.

I am basically doing what the picture you posted is doing with a slight twist...

The right side is solely a drain for the kitchen, the left acts as a drain and vent for the laundry.

I will also most likely be tying the vents for a floor drain and condensate drain into that foot vent.

Is this allowed?

 

[Reach4]

Most of PA is under IPC code. That allows AAVs. That can simplify venting.

 

[wwhitney]

I will also most likely be tying the vents for a floor drain and condensate drain into that foot vent.

Is this allowed?

No. Nothing may tie into the foot vent; vents can only be connected at 6" above the fixture flood rim level of all the fixtures involved. You'll need to get 6" above the kitchen sink flood rim level before you tie in.

So if you don't want to use AAVs, and if the laundry is on the floor below the kitchen as I understand it, you'd need to do the laundry and kitchen sink as below.

See this link for the IPC rules on island loop vents that apply in PA:

Chapter 9 Vents: Vents, Pennsylvania Plumbing Code 2018 | UpCodes

UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction

up.codes

Cheers, Wayne

 

[Pulse]

I assume this is for the off chance the island vent would get clogged? It certainly makes things a lot more difficult in my current setup.

Thank you

I was trying to avoid using AAVs

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One last thing, any reason two toilets cannot be fed off of a single 1/2" pex line. I will most likely be doing an uponor logic system for the water lines. I see no reason why each toilet would need its own 1/2" off of the same sub manifold.