01-31-2007, 08:23 AM
In a previous post I had asked about water lines but they are the least of my problems. I'm installing a bath on a 3rd floor but not pulling any permits. The new room will be in an alcove with the back wall being the outside of the house. The front wall will be half high then glass block this is the wall that the toilet will be on and no vent pipe will be possible because of the glass block. I can only run the 3" waste line in one direction and that will be between the floor joists. Going in the other direction would mean drilling huge holes in the already small joists. My plan is to put the tub or shower at the back outside wall and have it drain into a 3" pipe. This 3" pipe would continue running between the floor joists about 5' and then connect to a combination tee and y. Into the top of this I would put a stub pipe and closet flange for the toilet. Then a sanitary tee behind this which the sink with a 2" trap arm would drain into. The 3" waste pipe would continue about another 6 feet or so between the floor joists before making a 90 degree turn down to the basement. The question is at the back wall where the tub is can I somehow go out that wall and vent everything. Going up 3' or so above the floor level with a 2" vent pipe wouldn't be a problem because I'll have the back wall of the tub to go through. I know this isn't legal but I can't go through the roof or even to the existing stack. I have thought about a mechanical vent, AAV, but I don't want to hide it in a wall and cover it. I've attached a picture so that you can see what I'm dealing with.