I've been a lurker here for several years and I gotta say "Thanks"! This webpage and forum has been very helpful over the years. But, I'm about to tackle a plumbing project that I've never done before and need help. The wife and I will be finishing our basement. Right now, it is completely unfinished (poured walls and floor). Its a very old house (oldest portion around 1905 and had a significant addition in the 50's). Most of the existing plumbing probably isn't to code, but close. The biggest oddity I've found is there really isn't a soil stack that goes through the roof. Rather most of the fixtures are vented indepentandly through the roof.
As we plan out this project, we want to put in a full bath (seperate shower, seperate bath, lavatory, and toilet). The existing DWV system is above the concrete floor by about 3". As such, we will have to install a sewage ejector pump. I'd like to install this beneath the stairs. I've attached the floor plan (scale is big squares are 3' and small squares are 6") my wife wants and I think its all doable.
But, I don't know how to best design/layout the DWV system (there will not be any other plumbing additions in the basement). The green dot between the lavatory and shower is an existing 1.5" vent that I can easliy connect to and goes through the roof (it was a washroom sink vent that was abandoned on the first floor). It is currently not tied into anything. The green line on the wall behind the toilet is a wall that I "think" I can run a vent line through to the roof as well.
How would you run the DWV lines for this? Thank you very much in advance.
Oh and some additional information, I live in the very far north central Montana. No permits needed, but not sure on codes. But, I recognize that codes are there for a reason so would like to stick with them as much as possible. Thanks again.