Exterior standpipe vent

[range]

I am in the process of installing a drain on the exterior of my home that will be used as a standpipe for a water softener. The drain will be a 1-1/2" pipe that ties in to a 2" line for my washer that runs directly to the main 4" sewer line out to the street (see below diagram). The challenge I'm having is with how to vent this new drain. I prefer not to run a vent on the exterior of the home, so would an AAV be acceptable in this case? Or since there is a vent being used for the washer (approx 30 ft away), could I get by without a dedicated vent for the softener drain?

 

[Breplum]

Go with 2" drain size...use an AAV even though I've not run into any jurisdictions that allow AAVs. Backwards thinking know-nothing politics...AAVs work.

 

[Sponsor]

 

[range]

Go with 2" drain size...use an AAV even though I've not run into any jurisdictions that allow AAVs. Backwards thinking know-nothing politics...AAVs work.

Thank you. Have you had any issues with installing an AAV outdoors? It seems like they're only rated for indoor use, so am curious if this will cause any issues down the road.

 

[Reach4]

Consider running the softener drain into the house, and share the washer standpipe. There are air gaps made to share that way.

A softener drain is pressurized, so the flow does not have to be downhill.

 

[Michael Young]

Go with 2" drain size...use an AAV even though I've not run into any jurisdictions that allow AAVs. Backwards thinking know-nothing politics...AAVs work.

In my area, they don't give us any problems using AAV's. I reckon the only thing to do is to call the jurisdiction; tell them your plans, and make sure before you spend time and money on something that they won't pass

 

[Jeff H Young]

I would expect a fail if its inspected I dont nessesarily agree with it but no vent is generally an issue here including AAVs On new pools its common that a backyard cleanout gets a 3 inch trap and stanpipe for pool drains no vents not even AAVs Ive seen so its kind of a crap shoot. Mike Young mentined asking ahj not a bad idea if its a permit job . I think a lot of inspectors will let fly or not notice I think few would want to call it but they do have a job and bosses that might pressure them on stuff like this

 

[range]

Consider running the softener drain into the house, and share the washer standpipe. There are air gaps made to share that way.

A softener drain is pressurized, so the flow does not have to be downhill.

I like this idea and hadn't considered it. Unfortunately, it would require busting up a bunch of concrete which I'm not prepared to do right now. Thank you for the suggestion though.

 

[range]

Thanks for everyone's guidance on this. I think I will install the AAV with a 2" drain.

One more question: Are there any issues installing the AAV outdoors? I noticed Oatey says it's not approved, but am just curious if it will be fine or if it's just something I can expect to replace every few years.

 

[Reach4]

Most plastics, including softeners, will degrade in UV with time. Consider a cover or paint to block UV. Protect unpainted tanks too.

Here is another consideration: if an AAV on an outdoor standpipe fails (open or closed), you are unlikely to notice. Also, most softeners end up with a flow to the drain line that is fairly low. A siphoned trap probably gets refilled even if there is no vent to break the siphon that could occur during backwash or fast rinse.

If I made the rules, drum traps, which do not need vents to work, would be allowed for softener drains and condensate drains. I understand codes not allowing them for tubs, showers or especially kitchens. But for those applications that will not get solids, I think they should be permitted.

From a functional and allowed softener standpipe, 1.5 inches would be enough. Washing machines have much higher peak flow, plus they have suds. So for WMs, 2 inch certainly makes sense.

 

[Jeff H Young]

Range , is the 2 inch proposed a buried line going to the w/m along side the house?

Thanks for everyone's guidance on this. I think I will install the AAV with a 2" drain.

One more question: Are there any issues installing the AAV outdoors? I noticed Oatey says it's not approved, but am just curious if it will be fine or if it's just something I can expect to replace every few years.

issue is our code many think its a bit over bearing I do Im no fan of AAV but these are the type instances they shine. An AAV will never in my opinion be as good as a real vent through the roof but the issue to me is dose it need to be? In most cases I say yes it should be as good as a real vent and a real vent should be installed withen reason your case and others I think the hardship (cost) out weigh benefit if the aav were to go bad its easy enough to change and in reality you would almost surely never know. That said following code has advantages too like in a future sale or something but to me its not that bad or dishonest putting aav on an outside line like a bbq island sink or this. (and its possible that there are ways to get this aprooved Im not sure though Ive spent my entire career in CA and never used an AAV) Im just short of recomending you go ahead and put an aav but not there yet . plus you never mentioned permit is getting pulled or not if you pulled a permit again Id expect you might fail. If you do get aproval share how it transpired please , Good Luck!

 

[range]

Range , is the 2 inch proposed a buried line going to the w/m along side the house?

issue is our code many think its a bit over bearing I do Im no fan of AAV but these are the type instances they shine. An AAV will never in my opinion be as good as a real vent through the roof but the issue to me is dose it need to be? In most cases I say yes it should be as good as a real vent and a real vent should be installed withen reason your case and others I think the hardship (cost) out weigh benefit if the aav were to go bad its easy enough to change and in reality you would almost surely never know. That said following code has advantages too like in a future sale or something but to me its not that bad or dishonest putting aav on an outside line like a bbq island sink or this. (and its possible that there are ways to get this aprooved Im not sure though Ive spent my entire career in CA and never used an AAV) Im just short of recomending you go ahead and put an aav but not there yet . plus you never mentioned permit is getting pulled or not if you pulled a permit again Id expect you might fail. If you do get aproval share how it transpired please , Good Luck!

Yes the proposed line will be buried along the side of the house.

I am leaning toward using the AAV, as to your point the hardship outweighs benefit/risk. Feels like there is relatively little risk in doing this and there is an alternative should this not get approved.

 

[range]

Over the next few weeks, I'll be building out the standpipe with an AAV and getting the softener installed. Will report back with pictures on how it goes.

For anyone who is interested, I was able to find a UV rated AAV for outdoor use (also includes a screen for insects). The Studor Tec Vent appears to be one of (if not the only) option available that's designed for a smaller single fixture application. It's intended for commercial applications, so not as readily available as the Oatey AAVs or the Studor Mini Vent, but hopefully will last longer outside.

Thank you to everyone for all of the helpful advice. This was my first post and am very appreciative of everyone's thoughtful responses.

 

[Michael Young]

Thanks for everyone's guidance on this. I think I will install the AAV with a 2" drain.

One more question: Are there any issues installing the AAV outdoors? I noticed Oatey says it's not approved, but am just curious if it will be fine or if it's just something I can expect to replace every few years.

Outdoors is a bad idea. If you have freezing weather, that little flap can freeze shut, killing your vent

 

[Reach4]

Outdoors is a bad idea. If you have freezing weather, that little flap can freeze shut, killing your vent

It is a standpipe for an outdoor softener. In freezing weather, I would expect that to be damaged.

 

[range]

It is a standpipe for an outdoor softener. In freezing weather, I would expect that to be damaged.

Fortunately, freezing weather doesn't really happen where I'm located in Southern California, so I don't think this should be an issue for the softener, pipes, or AAV.