Toilet drain and vent (seattle WA)

[otusweb]

I'm adding a bathroom on the second floor and am running into an issue with the venting for the toilet.

I added an image of what i'm running into. Basically i have to run the drain (red) toward the outside wall because this is the only place where i can run the 3" drain line to the basement (joist are running parallel to the drain pipe in red). This wall is more that ten feet away so i have to vent the toilet before the line gets to the outside wall...

I could use the wall behind the toilet (wall on the left on the picture) to vent and go straight to the roof, but i don't know what fitting i could use to accomplish that as the drain and the vent would essentially go in totally different directions...

The wall in the back is also an option, although, same issue there, how would i get the vent in that wall?

Thank you
olivier

[phishfood]

If you have the depth in the joists, run all the way to the wall that you would install the vent in. Turn up with a short sweep, put a sanitary tee on top of that with the branch pointing to the toilet, and run the vent out of the top of the sanitary tee.

A street short sweep or street sanitary tee into the top of the short sweep would save you some depth, if you are really tight for space.

[otusweb]

Thanks. I have 9.5" so i think that will be enough. The only issue is that the top plate of my wall only has 6.5" as my joist are 6.5" (i added a beam so i'm dropping the ceiling a bit).

Any other idea that would be more compact (else i'll have to notch the top plate).

Thank you,
Olivier

[phishfood]

If you can drain the lavatory into the vent, you can catch the toilet as you pass by it on the way to the wall. The lavatory will wash the vent for the toilet, eliminating the dry flat vent.

[otusweb]

No Lavatory on the way to the wall unfortunately.

Could the arm coming from the outside wall be connected into a long combination Wee. The turn would connect to the closet bend the straight side would keep going to the back wall turn up and be the vent. I don't think this is legal, but i thought i'd ask.

Thanks

[otusweb]

Would the configuration at this URL be legal in Seattle under UPC?

Thank you, olivier

[Hyper48fan]

Yes, that is Legal per the UPC.