[snoman1]

OK, I think I'm in big trouble so I'm preparing for the worst.. but was wondering what may or may not come of this. Over the past 5 years of living in my house my wife and I decided to move to a new town. Problem I ran into was over the past 5 years I had done several additions to our lower level. (with no permits) and the new buyer wants everything up to date. In anycase I got all my permits and now have to set up inspectors for plumbing, electric, hvac. My concern now is that when I added a full bath room. I vagley remember someone telling me that I didn't need to vent my shower and sink because it was just water and as long as there were P-traps I'd be fine. The tub is at the end with drain and trap (2" pipe) under the concrete floor. 4 feet down from tub drain the sink ties into the system and from there about 3 feet to center of toilet ties into a Y pipe that goes to the toilet. The toilet 45s back to the main waiste line. I have never had a problem with any of the fixtures draining, flushing, gurggling nor any smell of any sort. The buyers home inspector didn't say a word to us.. So I'm wondering how this may go down with my inspectors at this point since I've committed to my building permits with finished/completed work done. If they tell me to tear it apart can I run a vent line from the back of the sink up and tie across to the stack pipe.. FYI the stack pipe has the toilet upstairs attached as well. Or do I have to some how get a line out side? I've added a sketch with a couple photos in it to show what's going on.. thanks.

[speedball1]

Your bathroom group looks neat, however,

I vagley remember someone telling me that I didn't need to vent my shower and sink because it was just water and as long as there were P-traps I'd be fine.

Bad Advice!! Every fixture that has a trap must have a vent or be wet vented. I can see at least four code violations in your drawing. 1) The upstairs bathroom group's draining past the unvented downstairs group. 2) The downstairs toilet, major fixture, is discharging past unvented minor ones, your tub and lavatory. 3) Illegal "S" trap on the lavatory and 4) the shower is unvented.
How I would get around this without too much hassle would be to change that "S" trap for a "P" trap and run a vent on the lavatory. This way the tub would be wet vented and the reast of the group would vent through the lavatory vent.

If they tell me to tear it apart can I run a vent line from the back of the sink up and tie across to the stack pipe..

No! You may not tie back to the main stack vent. However you might check the local codes to find out if you can install a AAV mechanical vent next to,the lavatory trap. That would vent the group without running a vent out the roof. Good luck, Tom

[snoman1]

Hi again,
I got my inspection and things didn't go as bad as I thought.. they will let me install what is called a studer vent above the sink.. and the other was my supply line to the toilet needs to be 3/4" pipe.. I'm not allowed to send cold water to all 3 with 1/2" pipe.. all and all not too bad.. a little drywall work and a couple pcs of pipe and the vent line and I'm done. Hope some can learn from this.. Thanks for your time!

[speedball1]

Glad you got fixed up with a minimum of hassle. Tom

[ballengerb1]

That Studor vent they Okd is an AAV like Tom mentioned, Studor is just one brand kind of like calling all gelatins Jello.