Bathroom drain venting

[Maack]

Hi all. The builder roughed in the drains for a tub/shower, a toilet and sink, into the basement slab. That was in 2014. The new bath walls will be 6 ft wide x 13 ft deep. My question is how do I vent these 3 fixtures? Thanks. Maack

 

[Reach4]

Ideally and normally, the drain lines were run so that only the lavatory needs a vent. The shower and toilet would be wet vented. The lavatory could be vented with an AAV, if there is no real vent pipe available. See a vent pipe above the lavatory drain maybe?

 

[Sponsor]

 

[Maack]

Thanks very much , an AAV would work nicely for the lav. There is no drain or vent pipe anywhere in that ceiling area, all fixtures on the main floor above are 20 to 25 feet away and are roof vented. The 3 stubbed out drains lines were capped and pressure tested and approved during the plumbing inspection phase. Is there a way to determine if the shower and toilet are indeed wet vented?

 

[Reach4]

Is there a way to determine if the shower and toilet are indeed wet vented?

There is always a way, so you probably did not mean that.

What you can do easily is to make sure that water goes down the the toilet and lavatory drains and disappears, and that water stands at the bottom of the trap under the tub/shower pipe.

If you are connected to a city sewer and this bathroom does not feed into a septic pit with a sump, I would also check with the neighbors downhill from you to ask if there is ever any sewer backup. If there is no lower neighbor, talk to the sewer department about the possibility to know if you want to implement measures before finishing the basement.

If you are not on city sewer, put getting your tank pumped on your calendar.

 

[Maack]

There is always a way, so you probably did not mean that.

What you can do easily is to make sure that water goes down the the toilet and lavatory drains and disappears, and that water stands at the bottom of the trap under the tub/shower pipe.

If you are connected to a city sewer and this bathroom does not feed into a septic pit with a sump, I would also check with the neighbors downhill from you to ask if there is ever any sewer backup. If there is no lower neighbor, talk to the sewer department about the possibility to know if you want to implement measures before finishing the basement.

If you are not on city sewer, put getting your tank pumped on your calendar.

 

[Maack]

Yes,the water does stand at the tub shower drain trap. The toilet and lav drain water does disappear. There have been no backups with 2 downhill neighbors There is a sewer backflow preventer that was installed for this rough in , about 15 feet away from the toilet drain , in the slab, downstream of the bath. It is on city sewer , no septic pit or pump.
This pic is standing about 20 back to include the backflow preventer access at the lower left.
Does that water standing in the trap, and the water disappearing in the toilet and lav drains indicate that it was layed out as wet vented?

 

[Reach4]

Does that water standing in the trap, and the water disappearing in the toilet and lav drains indicate that it was layed out as wet vented?

I don't know how somebody could know without a study with a camera and maybe more if you wanted to be really sure. If the rest of the plumbing seems competent, I would not be looking to spend I would guess $600 to 1000 to check if it was done properly to meet the IPC rules for wet venting. I am not a plumber or other pro.

 

[Maack]

Thanks for all your help, I really appreciate it, you have helped me tremendously, Thank you.