## horizontal venting versus wet venting

I'm remodeling a bathroom and have been researching proper venting as I lay out the plumbing. I have a standalone shower and tub and a dual bowl vanity and of course one toilet. The question I have is this...

My drain is on the on the western side of the room and the shower is on the east. The drain is about 3' from the eastern wall. I was going to run the south through one joist and then tee into a 2" drain line that would run down (horizontally) to the eastern drain and then run west (horizontally) the 3 feet to tie into a vertical vent. However, everything I'm reading seems to say that this is against code since it is a horizontal vent. However, if I were to tie in my vanity sink into that vertical vent line, that'd turn my 3' horizontal into a wet vent and that would be okay... Am I just a little off and this isn't truly considered a horizontal vent since it's within the 5'/8' (is it 5' or 8' critical distance for vent for 2") that is required for a vent for 2" pipe? My toilet is in the same situation... The 3" pipe drains straight down through the first floor into the basement. The house originall had a sink with 1 1/2" pipe teeing into the 3" drain pipe and a 1 1/2" vent near the sink for the 3" pipe as well. I was going to run horizontally 2' (2" pipe) from the 3" pipe/toilet to a side wall and then vent vertically, but again, this seems to be horizontal venting...

Are these okay to do? The other option on the shower would be run the shower drain back west 3' first, vent up, then do a U-turn to go back to the eastern drain... That's seems less than optimal... If the "horizontal" portion of the "vent' is within the critical distance, is it just considered "drain" and not "vent"?

Here's some wonderful ASCII art to help anyone not visualizing it...

|| (vent)
/= =(drain) ||
// U ||
// ||
=======_============_|

(vent)
||
(toilet) ||
| | ||
| |/ ======_|
| /
| |