I'm doing a remodel on my bathroom and adding a shower where a bath once was. I'm trying to figure out the best way to vent this. In this drawing I show 3 options.
-A would be to vent down from the shower trap about 5 feet to an existing vent. Is 5' of sharing a water drain too much length to then vent?
-B would be to tie into the drain that is currently used by another shower and "share" its vent. I have doubts about this because of whether the current vent would be effective since it is "up" from the draining angle of the drain. And I'm not sure two units could share a vent like this even thought they are not used at the same time. I don't have it on the drawing but the sink down form the current shower is vented straight up to the wet vent.
-C would be to move the previous drain a little ways and vent as shown to a current wet vent. The vent is just a couple of feet away.
I have real limitations with the structure of this house and how much I can change things. Any feedback would be great.