My basement was bare concrete with the stub outs being a 3" toilet, a 2" lav drain, and a 1.5" tub drain in the floor. I've read a ton but want to be sure there is not something simple I'm missing before I glue the connections. I have a single 2" pipe hanging from the ceiling (with a cap on it now) that I'm sure is to vent through. The 2" lav drain is actually a wet vent for the toilet so I'm only running a line from that and then a 1.5" line from the tub. I also want to add a bar sink with a 1.5" vent as well - all tying into the single 2" vent line with a couple fixtures. Here is a rough drawing....am I missing something? Does it matter how I combine the sizes and if I use a sinlge fixture or a couple to get this done? I have a 4 inch main stack.

first, the minimum size pipe allowed underground is 2"..
now, if you reverse the tub (make it a right hand drain rather than a left hand), you can drain it into the toilet vent pipe with a 2 inch "Y". no other vent needed.
keep it 2 inch with a 2 inch trap. put a 2 x 1 1/2 inch bushing into the trap inlet to recieve the tub waste.
you are good to go...

I get the impression that everything under the floor is already there. He was doing good until he added that bar sink drain. It CANNOT connect to the vent pipe.

as usual you are correct...
but i thought the bar sink vent is what is drawn.
if all the plumbing is installed for the basement then the bar sink drain is probably in as well.
nes pas??

Probably on the first floor, but who knows since we are not told. He said he "wants to add a bar sink" which implies it is not roughed in at this time.



Edited 1 times.

The stub outs were already in the floor from when the house was built including the 1.5" tub drain below the concrete floor level...which is a foot away so pretty obviously connected to the 1.5" vertical vent pipe.

This is all in a basement. The bar sink will drain into the main stack about 10 feet away. Does it need a vent? If so, I had hoped to simply tie it into the venting of the tub and lav. Do the number of fixtures and type matter in venting?


Thanks.

I have everything drawn in - the bar sink vent is what comes in from the right. The tub vent goes up and over and comes in from the bottom of the picture. The lav vent (also wet toilet vent) comes in from left of picture. I just need to tie all 3 vent pipes together and was wondering if there are any codes on type of venting fixtures or amount of vents on a single vent.

bar sink can vent as you have drawn..
there is a limit on how many fixtures you can vent into a 2" pipe but you are no where near that limit..

It seems like I've got conflicting answers on adding a bar sink....has information I added changed the fact that I can now add a bar sink?

Thanks.

the confusion comes as hj thought the bar sink is upstairs and drains into the bathroom proposed vent stack. that would be a no-no..

There was NEVER a prohibition to installing the bar sink, as long as it was installed properly. You showed ALL the drain piping, EXCEPT where you would connect it to the main line, therefore the ONLY pipe marked "bar sink" appeared to be its drain, not the vent.

FIRST; THE "IPC" ALLOWS 1 1/4" PIPING UNDERGROUND. NOT SURE WHICH PLUMBING CODE SD USES?

SECOND; IF USING A WET VENT SYSTEM FOR THE BATHROOM GROUP, THE BAR SINK NEEDS TO CONNECT DOWNSTREAM OF THE WET SYSTEM, AGAIN AS PER THE IPC

THIRD; THE 2" VENT IS THE MINMIUM ALLOW VENT (AS PER DRAWING) AND AS STATED, IT IS LARGE ENOUGH FOR THIS PROJECT

GOOD LUCK

If the minimum is 2" vent that I need to remove the 1.5" vent that is already under concrete?

I'm assuming the main stack (coming from floor above) runs down the side of the bathroom wall then 90s underground. I assume the 1.5: drain (vented) dumps into the main and the the toilet line, which the sink dumps into then dumps into the main about another 10 feet later or so. So, technically, the bar sink will dump upstream of where the toilet/lav & shower dump but they join the main as the bar sink never drains through those.