Venting a utility sink with an AAV

I am installing a utility sink in my boiler room and have a question about venting the drain with an AAV:

1. How far can the AAV be mounted from the sink? Ideally, I would like to mount the AAV in the garage by going through an adjoining wall... overall, it would be about 5 feet away from the sink.
2. My main reason for putting the AAV in the garage would be because I don't ever want the AAV to fail, and have septic gas leaking into the house. Should I even be concerned with that? Is Septic gas combustible?

AAV are not allowed by most codes. I would check with your local code inspector to see if they are allowed and what are the requirements. Personally I would just run a vent pipe to the existing vent system.

Don't really care about the code in this situation... no one will ever see this sink...

The existing pipe vent system is too far away to tap into from where I'm installing the sink. I'm looking to keep my costs down to a minimum on this project as well....

here we go again

Don't really care about the code in this situation... no one will ever see this sink...

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Don't we just love that concept? Codes are not about SEEING THE SITUATION. They are about health and sanitation. That attitude is why we are able to post "screw up of the day" pictures. In your case, the AAV will work, but not that far from the sink. The AAV MUST be at the trap, AND 6" above it. 4' or 5' away, you might just as well not have it, especially since "no one will ever see it". And, YES they do fail which is why you cannot hide them inside a wall.

hj said:

Don't really care about the code in this situation... no one will ever see this sink...

Don't we just love that concept? Codes are not about SEEING THE SITUATION. They are about health and sanitation. That attitude is why we are able to post "screw up of the day" pictures. In your case, the AAV will work, but not that far from the sink. The AAV MUST be at the trap, AND 6" above it. 4' or 5' away, you might just as well not have it, especially since "no one will ever see it". And, YES they do fail which is why you cannot hide them inside a wall.

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Thank you HJ for replying to this post. When they say they do not care about the code. I just bit my tongue and give up. Reason us pro's are here giving advice to the DIYers is to help you do the job properly If you do not want to take the advice of the pros then why even ask for it? The code has to be followed no matter who you are. It is there to protect and anyone else in the house, building, community. If and when you go to sell the home and the home inspector catchings something wrong with the code they will report it. Some towns will fine you for doing remodeling with out a permit and not having it inspected. It is best to follow the code (law) and get permits if they are required, make sure the task is going to meet the code and have it inspected.

ghint said:

Don't really care about the code in this situation... no one will ever see this sink...

The existing pipe vent system is too far away to tap into from where I'm installing the sink. I'm looking to keep my costs down to a minimum on this project as well....

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Yea, That's the spirit!
Screw the code!
We don't need no stinkin code!

Why does my house smell like poo?

My real main question here is whether or not septic gas is combustible. I don't want the aav to fail, and then blow up my house because this will be located in a very small boiler room. Is that a possibility? If it's not a possibilty, then I have no problem putting the aav right after the trap.

When I said "I don't care about the code" I was only referring to the use of "aav's" in my town. I still want this sink done the right way... all I was saying is that I don't have any other choice but to use an aav here.

There are always choices... some are more expensive to implement than others.... plain and simple. If your locality does not approve of AAV's - then you face potential issues down the road, if and when you decide to sell your house. If you intend to live there forever - then you, obviously, can do whatever your like. I, for one, like the ease of AAV's to get around sticky situations - but if the local code doesn't allow it - I don't use them.... Oh yeah... septic gas is combustible... ever try lighting a fart?

When I said "I don't care about the code" I was only referring to the use of "aav's" in my town. I still want this sink done the right way... all I was saying is that I don't have any other choice but to use an aav here.

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If you don't have other ways of venting, the the AAV, done right, will do the job.

It should be accessible for later replacement. None of the stuff lasts forever. And the next owner of the home shouldn't have to hire a detective to find out where a future problem may be.
There is nothing flammable from the vents. You will notice on the the roof, many vents letting sewer gas into the atmosphere and dispersing it. Unless you collect the gas from the "source" you aren't going to be lighting it up.
What you don't' want, is that dispersal in your home.
When I stayed a while in Guatemala, it was a nice upscale condo, with a very bad odor in the kitchen/dining area.
Beautiful tiles and bathroom fixtures, including bidets, nice inner garden courtyard, but they messed up on the plumbing rough-in.
For want of a few dollars in fittings, it smelled.

It was better in the maids quarters up on the roof.

Thanks for your reply Terry. I was never going to build it "into" a wall. I simply wanted to pass a pipe through the wall and mount the aav in my garage (out in the open) which is only 5 feet away.

Apparently, from what I have read, the AAV will not function when it is located that far away?

Here are the Studor instructions

http://www.ipscorp.com/pdf/studor/Installation.pdf

In 37 years of plumbing I have never even once ran into a fixture that I could not vent without an AAV.