[jerryls]

I'm putting a new 3 fixture bathroom into a cape cod house in NJ in the basement. The 3"(or 4") sewer line is below the basement level. Currently there is only one bathroom(3 fixture) on the main floor, plus a kithen sink. The stack is a 3" cast iron that goes out to the roof. It comes straight down into the basement floor at the back of the house. There is a utilty sink in the basement that was added after the house was built.
There are three 1.5" auxillary stacks also going up and out. One is near the kitchen sink and one is near the main floor bath tub and the 3'd was added at the connection to the downstairs utility sink. This third one is tied into either the 3" stack or to the kitchen 1.5" stack somewhere in the upstairs wall.
My plan was to add a toilet,sink and shower all close to the main stack line connected in the basement floor using Y tees.
My questions are;
1- Can I tee into the 1.5 inch vent with all three basment fixtures? I see some people say a 3" toilet drain requires a 2" vent, but I also see just as many arguements that a 1.5 is adequate.
2- If the toilet drain total length to the stack is less then 5' do I even need to vent it? The stack has the upstairs toilet tied into it, so I'm thinking the stack cannot be used as a wet vent?

3- If I need to vent the toilet, how do I tee off the toilet drain? Normally the toilet drains go to the rear of the toilet and the vent stack is teed in the wall. In my case the toilet drain will be in the cement floor going forward to meet the sewer line drain?

Any suggestions are appreciated.
Thanks!

 

[jerryls]

Toilet needs a minimum 2" vent.

"If your stack goes all the way through the roof you shouldn't need a vent if you're within the distance you specified above."

Alan, thanks for the reply. Yes all three fixtures will be less then 5'(total pipe distance) from the stack connected under the floor to the line that goes from the stack to the sewer. The stack goes straight out to the roof, but the upstairs toilet drain is also connected to that stack. I read conflicting statements that I can't do this for proper toilet ventilation? I just want to be sure.
Thanks Again.

 

[jerryls]

in my code, you cannot wet vent between floors. you also cannot wet vent a water closet with another water closet (one and two fixture unit traps only) you can run a vent up the wall and tie in to the original vent above the flood level of the upper fixtures, which is generally 42" above the floor.

Thanks- that is what i was afraid of- how do i tie into the new toilet drain for the new vent if it's going in the floor away from the wall? can i just use one of those vented elbows going back? it will always have a little water in it though?

 

[jerryls]

i think you're talking about a low heel 90... can't use them like that. i believe the only way they're allowed is with the heel on the top, makes it like a reducing san tee. you can use a wye for the vent when the pipe is horizontal, but the branch must be above the centerline of the drain. some pics or a drawing will help us tell you the best place to run it

Here is a picture of the existing stack/drain. The wall behind it is the back of the house. The new toilet will be to the right(where the yellow cabinet is). The drain will be in the floor connected with a Y toward the front of the house. I don't know how deep the sewer line is until I break up the cement, but it will be difficult to tee off the top of the new drain from the toilet for a vent, as I dont think the sewer line will be deep enough to do that. I plan on putting a 6" stud wall at the back of the house for other pipes, such as the sink and vent pipes that need to get over to the stack. The 1.5"(ID) galvanized pipe going up left of the stack is a vent pipe.
Thanks

 

[jerryls]

3 bathroom fixture and a kitchen sink are tied into it stairs. Howewver, the kitchen sink and the tub are auxilary vented out the roof with 1.5" pipe. I can ask the town plumbing inspector, but I was trying to avoid submitting twice. Besides typically in NJ when you ask a question, they tell you to hire a plumber, as they assume you don't know what you are doing. That is why I'm asking these questions to try and get it right the first time.
Thanks,
Jerry