DIYbanter - View Single Post - Adding a vent to my shop's waste line when putting in a shower

wrote:
Looking for advice on whether I need to add a vent to the waste line
downstream of the toilet (~3') where the new shower will tie in. A few
feet upstream from the toilet is the sink and the vent for the waste
line tees in there . I'm figuring I need to but I'm going to have to
move a heater and wreck some sheetrock on the other side of the wall if
I do. Any ideas?

Horizontal wet venting (i.e., using the horizontal drain line as part of the
vent stack) is bad mojo. Usually against codes, too. You'll want to at least
route a vent from near your shower tie-in over to the vent stack by the sink (or
just go straight up through the roof...but that's typically a lot more work).