Oscarmeyer28
New Member
Can you use a 2" vent for a bathroom group ? Toilet,shower, sink. Looking to wet vent it. Tub ties into 3" trunk, sink ties into 3" trunk, shower ties into 3" trunk then a 2" vent on the 3" trunk.
Under the IPC, you could use a 1.5" vent.Can you use a 2" vent for a bathroom group ?
But generally not like that. Each trap (sink, tub, shower) needs a vent connection on the trap arm before the trap arm falls more than one pipe inside diameter. The sink trap is highest, so it gets a 1.5" (minimum) dry vent connection. Then the sink drain turns down into the floor system and turns horizontal. The tub or shower joins it horizontally, and the combined drain needs to be 2". Then the shower or tub (respectively) joins it, and then the combined drain needs to be 3" if it is to wet vent a WC.Toilet,shower, sink. Looking to wet vent it. Tub ties into 3" trunk, sink ties into 3" trunk, shower ties into 3" trunk then a 2" vent on the 3" trunk.
Under the IPC, you could use a 1.5" vent.
But generally not like that. Each trap (sink, tub, shower) needs a vent connection on the trap arm before the trap falls more than one pipe inside diameter. The sink trap is highest, so it gets a 1.5" (minimum) dry vent connection. Then the sink drain turns down into the floor system and turns horizontal. The tub or shower joins it horizontally, and the combined drain needs to be 2". Then the shower or tub (respectively) joins it, and then the combined drain needs to be 3" if it is to wet vent a WC.
Cheers, Wayne
still not clear the shower venting . 2 inch vents are no problem thoughIt would look like this the sink would have a trap then use a sweep 90 to go down then a sweep 90 to the 3" trunk. I could probably put a 1 1/2" vent for the sink if I have too. My basement walls are icf so I can cut the styrofoam if I have to but I'd like to not....
still not clear the shower venting . 2 inch vents are no problem though
So that's not allowed, you need to vent the sink trap arm before the 90. [Which, BTW, for horizontal to vertical can be a quarter bend, it doesn't need to be long turn 90.] But as you are under the IPC, you can use an AAV at the sink (even on the trap arm within the sink cabinet, there are products made for that).It would look like this the sink would have a trap then use a sweep 90 to go down then a sweep 90 to the 3" trunk.
So if I went sink trap to a 45 then another 45 I could vent it this way since it wouldn't be a vertical to horizontal? I'm willing to use the AAV if for some reason going through the styrofoam is an issue.So that's not allowed, you need to vent the sink trap arm before the 90. [Which, BTW, for horizontal to vertical can be a quarter bend, it doesn't need to be long turn 90.] But as you are under the IPC, you can use an AAV at the sink (even on the trap arm within the sink cabinet, there are products made for that).
Then the rest of your diagram works. Assuming that's an ejector pit at the end of your drawing, keep the 2" vent through the roof rather than relying on the AAV to vent the whole bathroom group. The ejector pit will require a vent through the roof anyway, but the two vents can combine at a level above the highest point that the pit pumps to (or 6" above the sink flood rim, if that's a higher elevation).
Cheers, Wayne
I see ok great thanks for the help!Let me draw your attention to the earlier statement I made that answers your question:
"Each trap (sink, tub, shower) needs a vent connection on the trap arm before the trap arm falls more than one pipe inside diameter."
So, no using two 45s instead of a 90 doesn't help. You have to connect to a vent (dry, wet, AAV, whatever) before the trap arm turns down.
As to an AAV or putting a regular vent in your ICF, either one works.
Cheers,
Wayne