# saw this... discuss...



## plumb nutz (Jan 28, 2011)

Saw this while checking out a 3" gas line... Thought it was funny...


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## TX MECH PLUMBER (May 27, 2011)

Waste of money ..... And yes it's funny


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## Titan Plumbing (Oct 8, 2009)

Paraput walls are a pain. That may have just settled the issue.

I have a high-end strip center in Fort Worth that had issues with odors, raised all the stacks above the paraput and still had issues. Not everywhere and not constantly, but on occasion the $60. a plate Italian rest. will have issues.


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## plumb nutz (Jan 28, 2011)

Don't know how well you can see it, but them are AAVs on top of those vents..


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## Titan Plumbing (Oct 8, 2009)

I see that now...Did it solve the odor problem? :laughing:


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## Redwood (Sep 8, 2008)

Very interesting...
Put a vent through the roof then hack it with an AAV... :laughing:

That is some real dedication to shiot plumbing....:yes:


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## Tommy plumber (Feb 19, 2010)

Maybe they had a problem with vermin. I have installed screens on roof vents to keep rodents out, so maybe this was the reason. I can't imagine someone is such a stunod (dummy) as to put an AAV on top of a roof vent...:blink:


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## smellslike$tome (Jun 16, 2008)

This is funny looking but I have a couple of questions. I don't do any commercial new con so maybe there is a reason I am unaware of. It looks like c.i. coming through the roof (I guess to meet fire code) with 4' or 5', unsecured pvc extensions. I know why they are extended and why they used fernco's and pvc but is this allowed? I see mangled fernco's in drainage systems with some frequency. These are usually in piping systems that have at least some sort of support system. Isn't a 5' piece of pipe held vertically to another piece of pipe only by a fernco going to just blow around in the wind until it falls off? Now you have sewer gas being sucked right into the hvac equip don't you?

Also is it just my eyes playing tricks on me or in the last pic on the vent extension just beyond the one with the aav in the foreground, is that a vertical offset in mid air? If so, can anyone explain to me what that is about?


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## smellslike$tome (Jun 16, 2008)

I wonder if maybe they used a smaller diameter pvc pipe and slid it down inside the c.i. for a foot or two and used a reducing fernco coupling? I don't think that would be very smart but at least it would offer some support against the wind. As long as the pvc was still adequately sized for the load, I don't guess there would be a code violation would there? On the other hand, what happens when the band deteriorates or loosens or whatever, it's possible that the pvc extension falls through to the bottom of the stack (if it's straight with no offsets) and now you have a blockage that will not be cleared by any drain machine.

Hey maybe that's the reason for the vertical offset in the extension. So that one day if it falls, it won't fall all the way :laughing:!


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## Redwood (Sep 8, 2008)

smellslike$tome said:


> Hey maybe that's the reason for the vertical offset in the extension. So that one day if it falls, it won't fall all the way :laughing:!


But I don't see purple so whats to say the cement will hold.... :laughing:


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## futz (Sep 17, 2009)

smellslike$tome said:


> Also is it just my eyes playing tricks on me or in the last pic on the vent extension just beyond the one with the aav in the foreground, is that a vertical offset in mid air? If so, can anyone explain to me what that is about?


They probably ran out of couplings.


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## plumb nutz (Jan 28, 2011)

The strip is pretty much full of small restaurants... My guess is that they had an "odor" coming in from the air vents... Rather then try to clean the grease from and around there kitchen hood vents, it was assumed the plumbing vents were the issue. The vents are 20' away and over 8' tall.. before the additional AAVs. Never seen them outdoors.. are they even approved for outdoor use? Can't find one in my truck and the studor website is no help...
Heck they fail inside a building enough, can't imagine they would hold up with the elements too well...


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## PaulW (Jul 31, 2008)

The black AAVs have a charcol filter in them I believe if they are the same ones I have seen. They are trying to prevent the fresh air ducts from sucking in the sewer gases. We had a hotel here that we smoke tested because of odors when we released the vents we watched the air duct suck the smoke inside from about ten feet away in the open air! When we arrived on the roof we smelled the sewer gases instantly. It's a weird scenerio. Not sure how they resolved or if they did. We proposed to relocate the vents to the side.


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## DesertOkie (Jul 15, 2011)

PaulW said:


> The black AAVs have a charcol filter in them I believe if they are the same ones I have seen. They are trying to prevent the fresh air ducts from sucking in the sewer gases. We had a hotel here that we smoke tested because of odors when we released the vents we watched the air duct suck the smoke inside from about ten feet away in the open air! When we arrived on the roof we smelled the sewer gases instantly. It's a weird scenerio. Not sure how they resolved or if they did. We proposed to relocate the vents to the side.


We used the "Sweet Air" filters on one job. They usually work great for para pit roofs. We also had lots of issues with lead flashing not being tight to the vent (they just wrap it over) the open area would catch the gas and direct it back into the building through the spots between plywood sheets. I didn't believe it when we did the smoke test on that one.


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## PLUMBER_BILL (Oct 23, 2009)

Redwood said:


> Very interesting...
> Put a vent through the roof then hack it with an AAV... :laughing:
> 
> That is some real dedication to shiot plumbing....:yes:


I did not take a photo, but I did that one time to satisfy an inspector.

New House and it passed rough inspection, then on finale all fixtures in, house complety finished -- he [the inspector pulls his bullsheet] says vent from powder room below was too close to a window on the 2nd floor. He was right it was only 9'8" away. That he approved rough didn't matter. I put a Studor on. Stopped the tear out required.


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