AAV Placement Confusion

[nola000]

You mention same plane. The lav. trap is going behind a pedestal sink and will be about 16" off the finished floor. The tub trap is going under the tub, its a raised house. So they wont be on the same plane. Is that what you mean?
Im going to resize the picture so people can see it better.
When you say the tub will be vented by the lav. you mean if I put the AAV above the lav. not in the wet line? Right?

 

[nola000]

I cant believe how many replies Ive gotten coupled with a really good diagram with all the info you need and I still havent got a simple answer to a simple question. I guess nobody here really knows how to properly utilize an air admittance valve. I guess thats why plumbers are plumbers and hydrodynamic engineers are hydrodynamic engineers. I emailed Oatey and Studor. maybe they can help me.
Thanks yall for giving it a shot.

 

[Sponsor]

 

[NHmaster]

What you have discovered is that the vast majority of licensed plumbers regard AAV's as a mechanical device that will fail and therefore is of very limited use. An AAV is not an excuse to avoid running proper vents.

 

[nola000]

I agree. That does seem to be the consensus.
However, lots of things in life are engineered to fail. Big deal. Unscrew it and screw in a new one. Like I said before, no different than a light bulb. Could you imagine an electrician telling you to replace all your incandescent light fixtures with skylights and l.e.d.s running off solar panels because replacing light bulbs are an inconvenience?

I want to use AAVs because the combined effort to run a proper vent in my situation is far greater than any minor effort required to screw in a new AAV once every few years. Besides Ive read in a few places that the first AAVs that became available were less than reliable and that new gasket technology has improved sealing and longevity to a great degree. Ive seen some AAVs with lifetime warranties. Im guessing those first few AAVs in the U.S. market left a bad taste in some plumbers mouths and they have steered away from them ever since. AAVs have been used for years in Europe.

Im a carpenter. Not a plumber. Im not familiar with the way water flows. Im hoping that somebody out there has the knowledge to help me with what seems to me to be simple question to a simple problem, made even simpler with the help of a detailed diagram. Dont they test you with these sorts of problems when you get your plumbers license? Or do they just test your knowledge of code?

Im not trying to be a smart ass, but if you asked me how to install crown molding and gave me a diagram of your room I could give a very concise and detailed answer with instructions and a list of materials and tools needed to professionally complete the job. Maybe Im expecting too much.

 

[SewerRatz]

I cant believe how many replies Ive gotten coupled with a really good diagram with all the info you need and I still havent got a simple answer to a simple question. I guess nobody here really knows how to properly utilize an air admittance valve. I guess thats why plumbers are plumbers and hydrodynamic engineers are hydrodynamic engineers. I emailed Oatey and Studor. maybe they can help me.
Thanks yall for giving it a shot.

I hope you told Oatey and Studor where you live, they both will then tell you that you CAN NOT USE AN AAV in your home.

 

[Seaofnames]

If it fails when someone is not home the traps are siphoned dry, leaving methane to build up in the home. Then your furnace lights up and BAM. I'm sure your far away neighbour would notice if your house blew up. Then they ask you if you've done any work to the house recently or insurance wants to investigate the cause. They find a parially destroyed AAV on the ground. Have a good time defending the use of it when it made it 'easier' instead of running an extra 30 feet of pipe to the attic.

As far as the drawing is concerned and given your preference for doing it the easy way, just put the pipe right out the roof or outside wall wherever its easier, then you wont have to worry about the AAV failing AND its easier than attatching it to the main stack!!(You will still have problems with meeting code though, but it doesnt matter for you)

I'm sure if you were framing or finishing your house, you wouldn't take any shortcuts, would you? If you didnt cut something properly...aaahh just patch it with something, its easier than making a proper cut!

 

[NHmaster]

Some logic just can not be argued with

 

[nola000]

My problem with tying into the stack is that I dont have the tool to cut into the iron pipe. I also have a very low pitched roof with only about 3 feet of clearance at the ridge and I will be running a/c ducts up through there soon which the new proper vent might create clearance problems with.

Assuming I was able to get my hands on snap cutter ($$$) and I was able to find a good route to the main stack, what size vent tube would I use? Can I use 90 fittings in the vent and what other requirements would I have on the vent? If I were to run this vent off a tee on the lav. in the wall up into the attic and over to the main vent stack following code, based on my diagram would any of my other plumbing need any changes?

Here is a diagram with a proper vent.

http://i302.photobucket.com/albums/nn104/nola000/scan0002.jpg

Is this correct? Would this work? If I do it like this, would I need to make any other changes? It was mentioned that I should do something with the shower. The shower is about a foot from the main stack, I thought that meant I didnt have to vent it separately.

 

[Seaofnames]

You'd be ok with 2" vent. You dont want to oversize venting as well. Keep pitch on the vent so gases can rise. There is no other requirement for length or anything as long as the horizontal run is over the flood line(which you are if you are in the attic!!)

The other thing to consider though is putting any plastic pipe up there with the solvent(glue) being flammable. For commercial projects in my area they want all cast iron venting if it is behind a wall just for that reason. Since you already have a cast stack and if you rent/buy snap cutters...you might as well use cast on the venting once you leave the sink. Get some use out of the snap cutters AND it wont pose a possible fire hazard!.

 

[nola000]

So based on the diagram in the link, all I need to do to vent the pedestal sink is add a 1.5"x1.5"x2" tee and run a 2" pipe up the wall into the attic to the left about 11 feet glue on a 90 degree elbow and run back to the vent 7 feet and tie it into the iron stack with a tee?

How would the tub be vented? Would it use the same vent pipe as the pedestal sink?

What about the shower? Should it be vented too? Or is it close enough to the main stack?

Check this link...

http://i302.photobucket.com/albums/nn104/nola000/scan0002.jpg

Is that right?

 

[nola000]

Do I need to do this?

http://i302.photobucket.com/albums/nn104/nola000/scan0003.jpg

Vent the tub to the outside of the house. Or will it use the pedestal sink vent?

 

[JohnjH2o1]

The vent above the sink can be 1.5" and no vent is required on the tub. To cut the CI if you have a 4" hand grinder and a diamond cutter wheel will do the job for you.

John

 

[nola000]

Thanks. I have an angle grinder with a diamond wheel, that is what I planned on using.

 

[Terry]

You still haven't vented the shower.

And is the pipe going to the roof the vent for the downstairs plumbing?
If it is, you will have to tie the waste in below the waste for the downstairs plumbing.

 

[nola000]

I was told by a few people that the shower is close enough to the main vent stack that it would work for the shower. Its about 1-2 feet distance. Is this incorrect, or just not ideal? I dont mind if it drains a little slow because I use a high pressure, low volume shower head, but I dont want to be standing in a puddle either.

Its single story house. The vent I would add would be going up in the attic.

Should I put a little rise on the vent from the pedestal sink to the main stack?

 

[NHmaster]

Nothing in the drawing is proper. The 4" cast you are dumping into is the vent for the downstairs fixtures so when you use the upstairs bath you are effectively negating all the vent for the downstairs. beyond that, even if it was not the vent, the shower has no vent, the vent for the claw foot tub runs horizontally below the flood level rim of the highest fixture and I do not see a toilet anywhere in the drawing either. Time to call a professional in before you do something you will regret for years and years.

 

[nola000]

For the second time. There is no upstairs.

It is a single story, single family, raised home. The iron "main stack" is a combination drain/vent or "wet vent".

Here are the links, look at them again and give me a hand...

This is the original, before yall talked me out of using an AAV.
http://i302.photobucket.com/albums/nn104/nola000/scan0001-1.jpg

This is one showing a proper vent(I hope).
http://i302.photobucket.com/albums/nn104/nola000/scan0002.jpg

This is one showing a proper vent AND one for the tub(not sure if its needed. Input please).
http://i302.photobucket.com/albums/nn104/nola000/scan0003.jpg

 

[NHmaster]

In that case, dumping into it negates all of the vent for the other fixtures on that floor. You can not use it for a wet vent because you can only wet vent a bath group, not the entire house. Everything else I said remains the same.

 

[nola000]

"You can not use it for a wet vent because you can only wet vent a bath group, not the entire house."

Sorry. I need to give more info.

The wet vent that is in the diagram only serves the fixtures that are in the diagram. The only thing it serves that isnt in the diagram is a toilet that runs to the stack all by itself below the tie in for the rest of the fixtures.

 

[nola000]

One more time and I promise Ill go away...

http://i302.photobucket.com/albums/nn104/nola000/scan0005.jpg

How does that look? Will that function properly?