Hi,
we're building a garagmahal (2 car garage with upstairs apartment) - simple layout -
7x8 lav - upstairs with corner shower, toilet (outside wall), sink (opposite toilet) with a second sink through wall to 'snack area' - My question is venting - my reference book says that there is a top floor bathroom "exception" to stack venting, that a side-inlet T, can drain/vent toilet/shower, and on top of that a simple T to drain vent the two sinks.
Is this correct? i.e. to the 3" stack that vents through the roof I can directly T in all 4 appliances?
thanks
robalo

why don't you just run 1 1/2 out... say you have the tolet start there after the toilet throw a 3 x 1 1/2 wyeand vebt the toilet (or 3x2 wye and a 2 x 1 1/2 wye off and use it as a combination wastse and vent and catch your shower) or just as a vent. Ethier whay that will have your toilet and shower vented then throw another 3x2 wye off and catch your sinks and vent them using a 2x 1 1/2 x 1 1/2 and then run 1 1/2 up then tie all you 1 1/2" together and go out the roof once... does that make sense

I think you're saying that the all can be drained to the stack, but the sinks need to be vented separately (and that line joining the roof vent later... ) -
I guess the question is can they all be wet vented together?

I think you're saying that the all can be drained to the stack, but the sinks need to be vented separately (and that line joining the roof vent later....) -
I guess the question is can they all be wet vented together?

Yes the toilet and shower use the same vent that would be a "wet vent" and then run another vent up with the sinks and tie them together up top and go out the roof once
As for using one wet vent for the whole set up... NO in my opinion with out being out of distance on your vent s and I base tis OPINION off the standards that I have to follow which is the 2003 International Plumbing Code ,