Ask Me Help Desk - Drain inline vent stack pipe

Just bought a small 1-story house with what looks like new plumbing. The drain pipe is 4" pvc with the toilet, sinks, shower, and washing drain connected. There is a Oatey in-line vent along the way sticking up into a plumbing wall about a foot. There is no rood stack vent though, so my questions is whetehr one should be present, or does the Oatey in-line make it unneeded. This is a very old little house but I do want the drains to work right.

Most codes will call for at least one vent exiting the roof(because you can't use an aav on a toilet.) So yes, you should have a vent exiting the roof. Also, every fixute needs to be vented in one way or another, so one single aav for the whole system just doesn't cut it. YOu would need an aav for everyfixture, or better yet, run a vent for each fixture.

Quote:

Originally Posted by kayak1

Just bought a small 1-story house with what looks like new plumbing. The drain pipe is 4" pvc with the toilet, sinks, shower, and washing drain connected. There is a Oatey in-line vent along the way sticking up into a plumbing wall about a foot. There is no rood stack vent though, so my questions is whetehr one should be present, or does the Oatey in-line make it unneeded. This is a very old little house but I do want the drains to work right.

All your fixtures are inline on a 4" main that's using a AAV to vent the lot? That's so far out of any code that I know of the we jusy won't discuss it anymore. Having said said that, When broke into the trade there were plenty of older homes with "S"traps and only one vent that worked just fine. My advice? Live in it and see how they drain.

Good luck, Tom

As to the person who said he wouldn't discuss it anymore, then what are you doing here? I did not make the system, it's what was there already. To the others thanks for the replies. It's a cesspool, but will be connecting to city sewer in the fall. So we'll see how it goes. My old house was similar and had one vent pipe to the roof and everything was fine. At the very least, maybe I'll remove the aav and run a 2" vent through the roof. I didn't think the aav would give anyplace for the gasses to go which is what made me wonder. It would be impractical to run a vent from each thing, but adding one in place of the aav should be at least a very big improvement, if not all it needs.

Hi kayak1. Tom wasn't trying to be rude or insultive to you. I think he was merely saying that the current setup of your plumbing vent system was not worth discussing any further as far as codes go in today's standards, but other than that he is willing to give advice on how to make it right, and also mentioned that you should just live in the house as is. If you don't experience any problems with slow drians, or sewer gas, then the system is working just fine(code approved or not). Sometimes you just have to throw the book out the window and use your best judgement as to whether what you have works or not.

Final thought. If you want to make it up to code, it will require a lot of work and expense. I agree with Tom, just leave it as it is unless you start having issues with slow, gurgling drains, or sewer gas.

Ya want to come down on me for telling you the truth? Reread my post, I said that even though it was far out of code I thought you'd be OK. Ya want to discuss it?
Code violation#1) "S" traps(see image) are illegal . Check out your lavatory and kitchen sink.
Code violation #2) Iy's against code to discharge a unvented minor oness. How many fixtures are washed by your toilet?
Code violation #3) No main vent through the roof
Code violation #4) Misplaced AAV. Should be on every fixture except the one serviced by the main vent you're going to put up.
If you want to bring your unit up to code we can walk you through the process. My advice still stands. Try it out before you start tearing out and adding things.
Good luck in whatever you decide. Tom

I'm sorry, I did re-read Tom's helpful post right after I posted my reply and I hadn't read the whole thing. Apologies.

I did go back over there to do some more exploring. The kitchen sink also has a Y underneath there with a vent on top. So there are two.

But would it help to take the one next to the toilet and unscrew it and run it up through the roof? That would be easy enough and there would be a place for the sewer gas to exit. I would be especially thinking about that when connected to the city sewers next fall (thats the scheduled timerame). I like to meet code, but the house has other more pressing issues to tackle and we need to be in there this month. I just would feel better with a stack vent from that main 4" drain trunk going up to the roof for sewer gas to escape. Otherwise, since these vents are obviously one-way, where would it go?

Quote:

Originally Posted by mygirlsdad77

Hi kayak1. Tom wasnt trying to be rude or insultive to you. I think he was merely saying that the current setup of your plumbing vent system was not worth discussing any further as far as codes go in todays standards, but other than that he is willing to give advice on how to make it right, and also mentioned that you should just live in the house as is. If you dont experience any problems with slow drians, or sewer gas, then the system is working just fine(code approved or not). Sometimes you just have to throw the book out the window and use your best judgement as to whether what you have works or not.

Final thought. If you want to make it up to code, it will require alot of work and expense. I agree with Tom, just leave it as it is unless you start having issues with slow, gurgling drains, or sewer gas.

Quote:

would it help to take the one next to the toilet and unscrew it and run it up through the roof? That would be easy enough and there would be a place for the sewer gas to exit.

I always recommend a natural vent or air gap over a mechanical one.
Mechanical ones can fail.
Vents do not exhaust sewer gas. That would mean expelling air. Vents do just the opposite they pull air in to relieve suction caused by draining water.
To flow freely, drain pipes need air. Without air, water will glug down a drain like soda pop from a bottle. A plumbing vent plays the same role as that little second opening in a gasoline can. With the stopper closed, gas pours out slowly. But once the stopper is opened, the air entering the can allows the liquid to flow freely.
Also, the air supplied by a vent prevents siphoning action, which might otherwise pull water up out of traps and toilets and allow sewage gases to escape into the house. Instead, vents carry the gases through your roof. Sewer gas, composed largely of methane, is not only smelly, it is harmful and dangerous. Don't be tempted to install a substandard venting system, even if it means avoiding a lot of work.
A main vent is an extension of the waste stack and reaches upward through the roof. Branch vents tie into the main vent. Every plumbing fixture and appliance must be vented properly, either by tying into a main vent or by having a vent of its own that extends through the roof.
When installing a new fixture in a new location (not just replacing an existing fixture), venting is often the most difficult problem to overcome. Local codes require that venting adhere to specific dimension requirements. Research these requirements before you begin planning. Vent pipes are made of the same materials as drain pipes, although sometimes they are of smaller dimensions.
Run your main vent and try the others out before getting into major surgery. Good luck,Tom