Horizonal Wet Vent??

Hi all, its been a while. I think I may be laying out my bathroom groups the hard way. I saw a job today were the plumber was laying out the entire group using a single 3" vent on back end of drain line running through the bathroom. He brought the 3" vent down from roof and 90 under bathroom floor joist. He then wyed his shower, toilet, Lav and tub in a row into same 3" line. from there 90 down and to the basement soil line it went. I have been taking individual vents up and bringing them together in attic then through roof. Am I doing it the hard way??

Thanks,

Lar

Depends on what part of the country you live in, down here in the southeast one vent does a entire bath, up north and to the west seems like everything is vented.

Im up north. I think I may be overkilling the venting if that way is ok. The only thing is that if he has his WC before his lav wont that pull on the trap water if its so close??

What you saw is called "stack venting". To work properly, the toilet needs to be connected downstream of all other fixtures in that group.

venting

UNless the lavatory is tied into the vertical 3" vent, there is no way I can see it being installed without using a "S" trap using your description. One thing plumbers learn during their five year apprenticeship is that there are many things that can "look" good, but are in fact either bad ideas or illegal. From your description, you are seeing one of those "things".