Venting for stubbed 3/4 bath in basement

New house. The basement is stubbed with two vertical drains going into (coming out of) slab for sink and toilet and has a 12" x 12" open square in slab with a 2" horizontal drain (in gravel). BUT there aren't any more PVC pipes for venting. If I paid extra for it to be stubbed shouldn't that include VENTING? By default, venting is a major part of the plumbing system, so I would think if something like stubbing a basement is done for future use, then venting would be part of that package. I guess my question is, can the venting of these items be under the slab as well? If not, how am I supposed to use these to finish a bath now, if they are more than 20' away from the main venting stack for the upper floors?

vents

Those vents have to be connected to an existing vent pipe somewhere in the house or extended out through the roof as a separate vent. "roughing in" means whatever the plumber and builder agree that it means, whether that is just under the concrete, the entire pipe system including vents and drains, or even all the vents, drains, and water piping.

are you saying that all of these could tie into the venting system under the slab? I am pretty sure they all tie into the main sewer drain just before it leaves the foundation and nothing else.


shower drain ----->> toilet drain (45degree into secondary 4" line) ----->> lavatory drain (45 degree into secondary 4" line) ---> into main 4" drain/sewer line.

If this is the case, how in the world can I even use a AAV for the shower and toilet?

pipes

They tie into the sewer system under the slab. The venting all occurs above the floor. An AAV is a "bandage" when you cannot do it properly, and it will only work if the system is not connected to a pump pit.

hj said:

They tie into the sewer system under the slab. The venting all occurs above the floor. An AAV is a "bandage" when you cannot do it properly, and it will only work if the system is not connected to a pump pit.

Click to expand...

I understand that the stubs tie into the sewer system ( I don't need a pump and this is city sewer). However, I am trying to find out if I am screwed because the existing vent stack is at least 20 feet away from these stubs and I can tear into my finished 1st and 2nd floor walls to make a new vent stack. If I am screwed, is this normal plumbing practice to make someone feel good about having a stubbed basement, BUT also be screwed because you can't vent the stubbed area, which renders the stubs useless?

wet vent

Can I just use the lav vertical drain line for a wet vent (using an AAV) for all three traps? Or since the main drain line that all three connect to is 4" and horizontal am I fine with not worrying about venting as the main line shouldn't be closed off to allow for any pos./neg. pressure in this grouping of traps???? I am pulling my hair out and am about to just move forward with the installs and not worry about this crap.