Wet Vent vs. Dry Vent (and siphoning)

[Jb9]

Hello,

I know this is a contentious topic, but I am working through a 2-story design in which I can wet vent a tub and toilet (toilet lowest on the stack) or I could add a dry vent for each fixture. I will post some jpgs as I redraw my plans but I wanted to ask a few questions of the pros with more experience:

-Does siphoning occur when waste from a toilet passes by another fixture's entry point in the stack?
-Does siphoning occur less in designs where there is more horizontal branching and things don't move as violently?
-Can avoiding a modern high power toilet resolve this possibility? Is that a bad choice to consider?
-Some folks don't like to wet vent lavs to toilets due to siphoning risk. Thoughts?

I will post a couple side by side jpgs in a bit after I redraw.

Thanks.

 

[Terry]

A tub or lav over the toilet is fine. They are wet vented using 2" pipe.
You can't run a toilet past a lav or tub though.