Shower venting questions

[Landcruiser]

So in the process of remodeling my bathroom I am completely rearranging the fixtures with the exception of the toilet. I've included a diagram of what I would intend to do. My concern is the shower vent that runs horizontal out from under the shower pan. To be more precise this portion would actually have some slope to it about a half an inch over the course of the 18 in. Is this acceptable? Also if you look at the rest of the drawing is there anything that would seem obviously wrong? The 2-inch Line running off the page to the left heads to the sink and there's a vent coming in higher than what I've drawn for the sink.

 

[Landcruiser]

i think i have it figured out. if i do a shower with a rear middle drain, I cont put the drain on the vent wall and avoid the 18" run.

 

[Sponsor]

 

[Terry]

If the 3" pipe above the toilet only has the lav on it, then the shower could be vented there assuming the trap arm to the shower would be five feet or less and not more than 135 degrees of change. You can use 45's and get rid of two of the 90 bends. The unwashed flat vent doesn't fly.

 

[Landcruiser]

Thanks, Terry. not sure if you saw my second post, or not but I think I have it sorted. If I do the back wall drain for the shower, then the vent segment will be greater than 45 and should comply with code. I may be able to get rid of the 90's as you have suggested, but the straight run to the toilet vent is like 7 feet and I was under the impression that it was a no-go for that distance.