# Washers being used for wet vent?



## plumber78

I have seen a couple of posts where people have mentioned using a washer for a wet vent. Ohio uses the IPC (after adding in their own touches) and there is no way a washer would be allowed to be any part of a wet vent...nor should it. 

IPC states that any combination of fixtures within two bathroom groups located on the same floor level is permitted to be vented by a horizontal wet vent. A bathroom group is defined as a group of fixtures consisting of a water closet, lavatory, bathtub *or* shower, bidet and emergency floor drain. So if the layout of the house allows and as long as the piping is sized correctly, you can wet vent two separate bath groups on one wet vent. Note that this can be interpreted differently by different inspectors. I have had some let me use a double lav to vent a shower and a garden tub in the same bathroom. Others Interpret it as you are not able to wet vent two of the same fixture in the same bathroom...ie, shower and soaking tub are in the same bathroom so one of them would have to be individually vented. Most of the inspectors saw how idiotic that was and have backed off of that. 

I have been in the trade long enough to remember having to individually vent every fixture and having a 3" vent through the roof. When Ohio adopted IPC, everyone thought we were stepping backwards and that it was ****ty plumbing. It caused a huge uproar...mainly because no one took the time to understand it. The theory behind it was that with the lower gpf toilets and gpm faucets would not fill the pipe completely therefore allowing air to travel on the top half and essentially becoming the vent aka wet vent. 

I said all of that to say this. You put a washer into that wet vent, and it will send a large slug of water through the pipe that will more than like cause other traps to gurgle and then siphon. The new washers can pump such a high amount of water that they should be vented with an individual vent or common vent to the atmosphere (definitely should not use an AAV). 

Thought???


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## plbgbiz

Part of the WV requirement is also upsizing the pipe. An 1-1/4" lav drain must be increased to 2". 

Mechanically, an automatic clothes washer could serve as a wet vent effectively if the pipe size is increased enough. Not a legal wet vent but it would work.

For a washing machine, this would actually fall into the Combination Waste & Vent category rather than Wet Vent....umm, maybe.


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## Will

You could make a case it could meet code if it dumped into a laundry sink rather than a stand pipe with a combination waste and vent. Be a grey area


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## plbgbiz

Will said:


> You could make a case it could meet code if it dumped into a laundry sink rather than a stand pipe with a combination waste and vent. Be a grey area


Probably be a tough sell with Billy.


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## plumber78

You could dump a washer into a circuit vent. Combination waste and vent does not have an actual vent that comes off of it. The pipe is oversized to allow the drain to become the vent. You can only use a combination waste and vent for floor drains, sinks, lavs, and drinking fountains. It cannot be used on a sink with a garbage disposal. 

The dry vent portion must be sized one size larger if you have more than 40' to get out through the roof.


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## plumber78

Side note...what part of WV are you in plbgbiz? A couple of years ago, we were working for a contractor that kept running us deep in WV. I tried and tried to find a plumber that could do the work for them because it was a lot further than I wanted to go. I could not find anyone that wanted to do new construction.


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## Will

Since no where in code (IPC) does it say washer, I'd have to say it does not meet code even if it does say sinks are ok for combo, waste&vent


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## plumber78

Will said:


> You could make a case it could meet code if it dumped into a laundry sink rather than a stand pipe with a combination waste and vent. Be a grey area


 
Laundry sink (or any sink for that matter) is not in the definition of a bathroom group and cannot be used in a wet vent system. You can get around this if you can use a circuit vent, however there are limitations to this as well.


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## Will

Combination, waste, and vent has nothing to do with a bathroom group, maybe reread my post


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## plumber78

Will said:


> Combination, waste, and vent has nothing to do with a bathroom group, maybe reread my post


I'm sorry, I have to much going on and I read your post to quickly. Dumping a washer into a laundry tub used to be done for years as a way to handle the volume coming from the washer. It would probably work on a combination waste and vent, however, I would be worried that it could still pull the trap. I myself am not sold on CW&V for sinks. It is an option though that the code allows if you are in a pinch. If it were my house I would pipe it up 2" and instead of using a 90, use a san tee and put an AAV vent on it. That way you are oversized to handle the positive pressure and you have the AAV to keep you from siphoning the trap. That is just one of those plumbers preferences though and AAV's aren't even legal in some jurisdictions. 

Hope I didn't miss your context this time lol


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## plbgbiz

plumber78 said:


> Side note...what part of WV are you in plbgbiz? A couple of years ago, we were working for a contractor that kept running us deep in WV. I tried and tried to find a plumber that could do the work for them because it was a lot further than I wanted to go. I could not find anyone that wanted to do new construction.


It was an abreviation.

Wet Vent requirement, not West Virginia. Sorry for the confusion.

Never been to West Virginia.


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## rjbphd

plbgbiz said:


> It was an abreviation.
> 
> Wet Vent requirement, not West Virginia. Sorry for the confusion.
> 
> Never been to West Virginia.


Ever been to DV??? Lol


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## plbgbiz

rjbphd said:


> Ever been to DV??? Lol


No,
But I've been to Oklahoma. :laughing:


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## Tommy plumber

plumber78 said:


> I have seen a couple of posts where people have mentioned using a washer for a wet vent. Ohio uses the IPC (after adding in their own touches) and there is no way a washer would be allowed to be any part of a wet vent...nor should it.
> 
> IPC states that any combination of fixtures within two bathroom groups located on the same floor level is permitted to be vented by a horizontal wet vent. A bathroom group is defined as a group of fixtures consisting of a water closet, lavatory, bathtub *or* shower, bidet and emergency floor drain. So if the layout of the house allows and as long as the piping is sized correctly, you can wet vent two separate bath groups on one wet vent. Note that this can be interpreted differently by different inspectors. I have had some let me use a double lav to vent a shower and a garden tub in the same bathroom. Others Interpret it as you are not able to wet vent two of the same fixture in the same bathroom...ie, shower and soaking tub are in the same bathroom so one of them would have to be individually vented. Most of the inspectors saw how idiotic that was and have backed off of that.
> 
> I have been in the trade long enough to remember having to individually vent every fixture and having a 3" vent through the roof. When Ohio adopted IPC, everyone thought we were stepping backwards and that it was ****ty plumbing. It caused a huge uproar...mainly because no one took the time to understand it. The theory behind it was that with the lower gpf toilets and gpm faucets would not fill the pipe completely therefore allowing air to travel on the top half and essentially becoming the vent aka wet vent.
> 
> I said all of that to say this. You put a washer into that wet vent, and it will send a large slug of water through the pipe that will more than like cause other traps to gurgle and then siphon. The new washers can pump such a high amount of water that they should be vented with an individual vent or common vent to the atmosphere (definitely should not use an AAV).
> 
> Thought???









My code requires that any additional fixtures in addition to the horizontal wet vent bathroom group(s) shall discharge downstream of the horizontal wet vent.

The idea of not permitting the washing machine in your example to discharge upstream is to protect the traps of the bathroom as we all know. However, with the low flow fixtures all being installed, I wonder if the W/M being allowed to discharge upstream would assist in washing waste out of the 3" drain. 

On the flip side, I would personally be worried about soap suds coming out of, for example, the tub overflow.


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## plumber78

Tommy plumber said:


> My code requires that any additional fixtures in addition to the horizontal wet vent bathroom group(s) shall discharge downstream of the horizontal wet vent.
> 
> The idea of not permitting the washing machine in your example to discharge upstream is to protect the traps of the bathroom as we all know. However, with the low flow fixtures all being installed, I wonder if the W/M being allowed to discharge upstream would assist in washing waste out of the 3" drain.
> 
> On the flip side, I would personally be worried about soap suds coming out of, for example, the tub overflow.


Our code requires anything else to tie in downstream as well. I completely understand what you are saying about running the washer through the wet vent. I would think it would work fine if you gave the water from the washer time(distance) to slow down and level out in the pipe before it hit the wet vent. Here, if you have a stack dropping from an upper floor, it has to run 10X the pipe diameter before any branch can tie into it to give the hydraulic jump that is created when the water hits the base of the stack time to level out. 

You touched on lower consumption being an issue. I have a house built slab on grade that has had a back up a couple of times in the last couple of years and the owner is positive there is something wrong with the system. We have run our camera through and the pipe appears to be sloping fine. The bathroom that is the problem is at least a 50' run to tie into the rest of the plumbing in the house. I am pretty sure that it is a result of the lower gpf toilets and there just not being enough water to carry the waste to the main sewer. They are an older couple and I am sure that bathroom probably does not get used a lot. We have Gerber Viper toilets in the house and if you install an old Gerber flapper in them, you can cheat and get a lot more than 1.6 gpf. The toilet will probably actually double flush, but I am almost certain it will take care of the issue. I wish I had a washer to run through this line...that would take care of it :laughing:.


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## plumber78

plbgbiz said:


> It was an abreviation.
> 
> Wet Vent requirement, not West Virginia. Sorry for the confusion.
> 
> Never been to West Virginia.


 
 Please pardon a couple of my posts from yesterday. This week has been crazy. I have been working 14 hr days in the office and I literally had no sleep the night before because I just could not get my brain to shut off. Things were a little foggy for me yesterday :laughing:


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## Tommy plumber

plumber78 said:


> Our code requires anything else to tie in downstream as well. I completely understand what you are saying about running the washer through the wet vent. I would think it would work fine if you gave the water from the washer time(distance) to slow down and level out in the pipe before it hit the wet vent. Here, if you have a stack dropping from an upper floor, it has to run 10X the pipe diameter before any branch can tie into it to give the hydraulic jump that is created when the water hits the base of the stack time to level out.
> 
> You touched on lower consumption being an issue. I have a house built slab on grade that has had a back up a couple of times in the last couple of years and the owner is positive there is something wrong with the system. We have run our camera through and the pipe appears to be sloping fine. The bathroom that is the problem is at least a 50' run to tie into the rest of the plumbing in the house. *I am pretty sure that it is a result of the lower gpf **toilets and there just not being enough water to carry the waste to the **main sewer. *They are an older couple and I am sure that bathroom probably does not get used a lot. We have Gerber Viper toilets in the house and if you install an old Gerber flapper in them, you can cheat and get a lot more than 1.6 gpf. The toilet will probably actually double flush, but I am almost certain it will take care of the issue. I wish I had a washer to run through this line...that would take care of it :laughing:.









You hit the nail right on the head. I used to work for a company in which the service manager would suggest a pressure-assist W/C for the scenario that you have with that customer. The line carry as it's called, is a longer horizontal distance with a pressure-assist W/C than for a regualr gravity W/C. I am aware that there was such an issue with pressure-assist W/C's in the past, however, I would make a recommendation for the pressure-assist, because in my opinion, getting a couple of good years out of the pressure-assist outweighs the constant recurring stoppages. If the pressure-assist needs maintenance in time, that would be a better option than living with stoppages. Just my thoughts. http://www.terrylove.com/forums/showthread.php?17959-Toilet-drain-line-carry-question


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## crown36

plbgbiz said:


> Part of the WV requirement is also upsizing the pipe. An 1-1/4" lav drain must be increased to 2".
> 
> Mechanically, an automatic clothes washer could serve as a wet vent effectively if the pipe size is increased enough. Not a legal wet vent but it would work.
> 
> For a washing machine, this would actually fall into the Combination Waste & Vent category rather than Wet Vent....umm, maybe.


 Wow! They allow the drain serving a lav to be sized at 1.25 in your area?? Here, we can use a 1.25 trap for a lav, but it must connect to a 1.5 drain.


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## plumber78

Tommy plumber said:


> You hit the nail right on the head. I used to work for a company in which the service manager would suggest a pressure-assist W/C for the scenario that you have with that customer. The line carry as it's called, is a longer horizontal distance with a pressure-assist W/C than for a regualr gravity W/C. I am aware that there was such an issue with pressure-assist W/C's in the past, however, I would make a recommendation for the pressure-assist, because in my opinion, getting a couple of good years out of the pressure-assist outweighs the constant recurring stoppages. If the pressure-assist needs maintenance in time, that would be a better option than living with stoppages. Just my thoughts. http://www.terrylove.com/forums/showthread.php?17959-Toilet-drain-line-carry-question


 
Thank-you for that link. :thumbsup: I may have to show my customer that video. We have a training center here at our shop that we used up to a year ago for apprenticeship training for the PHCC as well as to go over things with our own guys. We have a clear drain piping set up for a bathroom group upstairs in order to see the drains in action. I would love to set up a long line like what is in this video to be able to test different toilets.


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## crown36

plumber78 said:


> I have seen a couple of posts where people have mentioned using a washer for a wet vent. Ohio uses the IPC (after adding in their own touches) and there is no way a washer would be allowed to be any part of a wet vent...nor should it.
> 
> IPC states that any combination of fixtures within two bathroom groups located on the same floor level is permitted to be vented by a horizontal wet vent. A bathroom group is defined as a group of fixtures consisting of a water closet, lavatory, bathtub *or* shower, bidet and emergency floor drain. So if the layout of the house allows and as long as the piping is sized correctly, you can wet vent two separate bath groups on one wet vent. Note that this can be interpreted differently by different inspectors. I have had some let me use a double lav to vent a shower and a garden tub in the same bathroom. Others Interpret it as you are not able to wet vent two of the same fixture in the same bathroom...ie, shower and soaking tub are in the same bathroom so one of them would have to be individually vented. Most of the inspectors saw how idiotic that was and have backed off of that.
> 
> I have been in the trade long enough to remember having to individually vent every fixture and having a 3" vent through the roof. When Ohio adopted IPC, everyone thought we were stepping backwards and that it was ****ty plumbing. It caused a huge uproar...mainly because no one took the time to understand it. The theory behind it was that with the lower gpf toilets and gpm faucets would not fill the pipe completely therefore allowing air to travel on the top half and essentially becoming the vent aka wet vent.
> 
> I said all of that to say this. You put a washer into that wet vent, and it will send a large slug of water through the pipe that will more than like cause other traps to gurgle and then siphon. The new washers can pump such a high amount of water that they should be vented with an individual vent or common vent to the atmosphere (definitely should not use an AAV).
> 
> Thought???


 In my opinion, the wet vent relies on the concept of employing over sized piping and the low probability of all the fixtures on the wet vent being used at the same time. I would not be in support of the ACW or a Laundry sink receiving dishcharge from a ACW to be wet vented. Would it work? Sure. But overall there would be more problems than none.

Just for laughs, I think it would be a funny sight to see every fixture being used at the SAME time. Picture that!


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## plumber78

Triplecrown24 said:


> In my opinion, the wet vent relies on the concept of employing over sized piping and the low probability of all the fixtures on the wet vent being used at the same time. I would not be in support of the ACW or a Laundry sink receiving dishcharge from a ACW to be wet vented. Would it work? Sure. But overall there would be more problems than none.
> 
> Just for laughs, I think it would be a funny sight to see every fixture being used at the SAME time. Picture that!


 
Agreed. They are figuring that more than likely only one person is using one fixture at a time in a bathroom group. Even in our non inspected areas, I would never have one of my guys wet vent anything with a ACW. You could get away with a sink probably, but I don't even want them doing that. You start doing things that are not to code, and other companies will see it and start talking. We try to hammer quality to our guys all the time.


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## plumber78

Triplecrown24 said:


> Wow! They allow the drain serving a lav to be sized at 1.25 in your area?? Here, we can use a 1.25 trap for a lav, but it must connect to a 1.5 drain.


 
Minimum size drain in the IPC code is 1-1/4". You can carry 1 DFU on that. I have never seen anyone run 1-1/4 drain line before though. 1-1/2" is standard.


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## crown36

plumber78 said:


> Minimum size drain in the IPC code is 1-1/4". You can carry 1 DFU on that. I have never seen anyone run 1-1/4 drain line before though. 1-1/2" is standard.


 I'm going to challenge this, somewhat...You can use a 1.25 TRAP. But it MUST connect to a 1.5 drain. Least here in MI. Our plumbing code is adopted from the IPC. But as we all know, even if we adopt to IPC, BOCA, UPC...etc, things can vary for your State or Municipality. I know if I walked into the supply house and asked for a 1.25 San-T, they would look at me like I was crazy! Sort of like how the code book talks about 2.5" pipe. I have been plumbing just shy of 2 decades, and I have yet to use a length of 2.5" DWV pipe!


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## plumber78

Triplecrown24 said:


> I'm going to challenge this. Perhaps it could be how it's worded.
> 
> You CANNOT run 1.25 'Drain' for a lav. Period.
> 
> You can use a 1.25 TRAP. But it MUST connect to a 1.5 drain.
> 
> Least here in MI. and our plumbing code is adopted from the IPC.


2012 IPC code book...there is somewhat of a discrepancy...table 710.1(1) lists 1-1/4 as a building drain and sewer size, however if you look at table 710.1(2) which deals with horizontal fixture branches and stacks it shows 1-1/2" as being the smallest branch size. 1-1/4" can definitely be used for venting. I don't know why anyone would ever want to though.

Agreed...we are just trying to show how much code we know :laughing::thumbup:


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## crown36

plumber78 said:


> 2012 IPC code book...there is somewhat of a discrepancy...table 710.1(1) lists 1-1/4 as a building drain and sewer size, however if you look at table 710.1(2) which deals with horizontal fixture branches and stacks it shows 1-1/2" as being the smallest branch size. 1-1/4" can definitely be used for venting. I don't know why anyone would ever want to though.
> 
> Agreed...we are just trying to show how much code we know :laughing::thumbup:


 So true. One thing about thee old code book is a lot of it is open to too much interpretation. And if the inspector wants to have his way, he can just go to 102.9


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## plumber78

LMAO...I just looked that up and Ohio took that right away from their inspectors. It is in my IPC book but not the Ohio revised lol. I guess if it's not in our book we can't do it and they can't require it.


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## crown36

Plumber78: When does Ohio switch to the 2012 code? We switch over in Michigan on January 17th. Again, we will be adopting from the IPC.


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## crown36

plumber78 said:


> lmao...i just looked that up and ohio took that right away from their inspectors. It is in my ipc book but not the ohio revised lol. I guess if it's not in our book we can't do it and they can't require it.


 sweet!


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## plumber78

Triplecrown24 said:


> Plumber78: When does Ohio switch to the 2012 code? We switch over in Michigan on January 17th. Again, we will be adopting from the IPC.


I am not sure to tell you the truth. I know we are adopting the new lead requirements starting January, but I don't think that they are due for a new code cycle yet. We just had a revision a year ago. There is a lot of turmoil down at the state right now. Our lead inspector for the state, passed away. He was very well respected and is leaving a huge hole down there. Hopefully, they will be able to find someone as good as he was to replace him.


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## Ghostmaker

Only bathroom group fixtures are allowed on a wet vent. Washers and utility sinks are not a bathroom group fixture. 

*BATHROO*M *GROUP*. A group of fixtures consisting of a water closet, lavatory, bathtub or shower, including or excluding a bidet, an emergency floor drain or both. Such fixtures are located together on the same floor level.

Wet vent sizing are determined by 909.3


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## plumber78

Ghostmaker said:


> Only bathroom group fixtures are allowed on a wet vent. Washers and utility sinks are not a bathroom group fixture.
> 
> *BATHROO*M *GROUP*. A group of fixtures consisting of a water closet, lavatory, bathtub or shower, including or excluding a bidet, an emergency floor drain or both. Such fixtures are located together on the same floor level.
> 
> Wet vent sizing are determined by 909.3


 
Agreed...I think we let the conversation turn hypothetical concerning what might work. Our company would never run anything through a wet vent that is not a part of the bathroom group....even in non inspected areas.


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## Will

Combination, Waste and Vent work well. Infact I'd say a 3" run to a kitchen sink with a combination, waste, and vent would outperform a standard 2" kitchen sink drain with a vent. and yes I do know that if a garbage disposer is there code requires a vent even on a combination, waste, and vent system.


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## DMJ PLUMBER

After reading this thread I've realised how different Canadian plumbing code is as compared to American. Up here the one main rule with wet venting is that the most upstream fixture (the fixture which vents all the other wet vented fixtures) must discharge into a vertical waste pipe. Therefore in theory a washing machine could wet vent other fixtures as long as it discharged in to a vertical waste pipe (also referred to as a continuos waste and vent).

I don't agree with the comment about a washing machine producing a large slug of water in to a drainage system. The rate of flow on most machines is not very much, especially with the advent of high efficiency washers which don't use much water at all. What poses a greater risk to the drainage system from a washing machine is the potential sud zones it may generate which could create other unwanted symptoms in the system.


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## rjbphd

DMJ PLUMBER said:


> After reading this thread I've realised how different Canadian plumbing code is as compared to American. Up here the one main rule with wet venting is that the most upstream fixture (the fixture which vents all the other wet vented fixtures) must discharge into a vertical waste pipe. Therefore in theory a washing machine could wet vent other fixtures as long as it discharged in to a vertical waste pipe (also referred to as a continuos waste and vent).
> 
> I don't agree with the comment about a washing machine producing a large slug of water in to a drainage system. The rate of flow on most machines is not very much, especially with the advent of high efficiency washers which don't use much water at all. What poses a greater risk to the drainage system from a washing machine is the potential sud zones it may generate which could create other unwanted symptoms in the system.


2 posts already?? Your statement means nothing til ur introduction is posted..


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## Leach713

In tx wet venting is not allowed?


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## justme

Leach713 said:


> In tx wet venting is not allowed?


sure it is , even in the land of UPC Houston Texas.


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## Leach713

Ok so how come I have been told different ,
And when you got take your jman test I been told they will do deductions on your house , if you wet vent.


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## MTDUNN

Leach713 said:


> Ok so how come I have been told different , And when you got take your jman test I been told they will do deductions on your house , if you wet vent.


Ever heard of a stack vent?


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## justme

Leach713 said:


> Ok so how come I have been told different , And when you got take your jman test I been told they will do deductions on your house , if you wet vent.


Because the state wants you to learn the right way to plumb , as for being told something make sure you are listening to the right people. Wet venting is allowed if there is no other eay to do it.


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## Leach713

MTDUNN said:


> Ever heard of a stack vent?


Yes sir


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## Ghostmaker

plumber78 said:


> Minimum size drain in the IPC code is 1-1/4". You can carry 1 DFU on that. I have never seen anyone run 1-1/4 drain line before though. 1-1/2" is standard.


Minimum size drain on a wet vent is 1.5 inch and can only carry 1 DFU.


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## FEDguy

plumber78 said:


> I have seen a couple of posts where people have mentioned using a washer for a wet vent. Ohio uses the IPC (after adding in their own touches) and there is no way a washer would be allowed to be any part of a wet vent...nor should it.
> 
> IPC states that any combination of fixtures within two bathroom groups located on the same floor level is permitted to be vented by a horizontal wet vent. A bathroom group is defined as a group of fixtures consisting of a water closet, lavatory, bathtub or shower, bidet and emergency floor drain. So if the layout of the house allows and as long as the piping is sized correctly, you can wet vent two separate bath groups on one wet vent. Note that this can be interpreted differently by different inspectors. I have had some let me use a double lav to vent a shower and a garden tub in the same bathroom. Others Interpret it as you are not able to wet vent two of the same fixture in the same bathroom...ie, shower and soaking tub are in the same bathroom so one of them would have to be individually vented. Most of the inspectors saw how idiotic that was and have backed off of that.
> 
> I have been in the trade long enough to remember having to individually vent every fixture and having a 3" vent through the roof. When Ohio adopted IPC, everyone thought we were stepping backwards and that it was ****ty plumbing. It caused a huge uproar...mainly because no one took the time to understand it. The theory behind it was that with the lower gpf toilets and gpm faucets would not fill the pipe completely therefore allowing air to travel on the top half and essentially becoming the vent aka wet vent.
> 
> I said all of that to say this. You put a washer into that wet vent, and it will send a large slug of water through the pipe that will more than like cause other traps to gurgle and then siphon. The new washers can pump such a high amount of water that they should be vented with an individual vent or common vent to the atmosphere (definitely should not use an AAV).
> 
> Thought???


Why wouldn't AAV work on a clothes washer? HE washers use hardly any water. That's what most folks are going too.


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## plumber78

FEDguy said:


> Why wouldn't AAV work on a clothes washer? HE washers use hardly any water. That's what most folks are going too.


It isn't the amount of water that is put into the washer that is the issue, it is the amount that is pumped out at one time that causes the problem. Years ago we used to be able to run 1-1/2" drains for washers. That was changed to 2" and now 3" must be run to the base of washer drain. From what I am understanding, these increases are because the washers are pumping more gpm than before. An AAV should not be used on anything that uses a pump. They are designed for negative pressure situations only and a pump will put a positive pressure on the system.


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## FEDguy

plumber78 said:


> It isn't the amount of water that is put into the washer that is the issue, it is the amount that is pumped out at one time that causes the problem. Years ago we used to be able to run 1-1/2" drains for washers. That was changed to 2" and now 3" must be run to the base of washer drain. From what I am understanding, these increases are because the washers are pumping more gpm than before. An AAV should not be used on anything that uses a pump. They are designed for negative pressure situations only and a pump will put a positive pressure on the system.


Thanks


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## jtplumber

Here in Denver we have to run an isolated 3" line to the awb due to gpm being discharged and that it is a suds producing fixture. However code states that if a floor drain is designated to that wash room it can be wet vented off the vertical 2" drain from awb but still must increase to 3" before horizontal run. We do this quite often in new construction although we deep seal the trap and use max devoloped length for awb standpipe.


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## Chris3topher271

UPC says 2 bathroom groups can be horizontally wet vented. The bathroom group definitions for sanitary drainage doesn't include domestic clothes washers nor is it defined in section 908.2. That tells me no. Although you could argue that if you only wet vented 1 bathroom and a clothes washer that you are not exceeding 2 bathroom groups worth of DFU's.


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## plumbdrum

If you search further under wet venting it says you can't use washing machine or kitchen, basically everything is fair game. I've wet vented floor drains with urinals, WC with a tub. . I think the misconception of wet venting is there always has to have a lav and a WC involved in the Wet vent, which is not true. You could wet vent a tub with a shower if you lay your fittings out right.

Sent from my iPhone using PlumbingZone


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## BC73RS

plumbdrum said:


> If you search further under wet venting it says you can't use washing machine or kitchen, basically everything is fair game. I've wet vented floor drains with urinals, WC with a tub. . I think the misconception of wet venting is there always has to have a lav and a WC involved in the Wet vent, which is not true. You could wet vent a tub with a shower if you lay your fittings out right.
> 
> Sent from my iPhone using PlumbingZone


I agree we're allowed to use any fixture as long as the trap doesn't exceed 2".
On the other hand I would never use a C/W as a wet vent, a suds zone to me has always been a red flag, positive pressure and all that.


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## plumbdrum

BC73RS said:


> I agree we're allowed to use any fixture as long as the trap doesn't exceed 2". On the other hand I would never use a C/W as a wet vent, a suds zone to me has always been a red flag, positive pressure and all that.


Out of curiosity , why can't you wet vent a 3" trap? I doesn't make sense.

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## plbgbiz

ACW's are prohibited from wet venting. There is an underlying premise behind wet venting being an accepted practice in bathroom groups only. It consists of a low probability of simultaneous discharge, Significant oversizing of the drain pipe, and a limited number of DFU's allowed.

Figure 912.1(13) specifically shows ACW's as prohibited along with stack discharge into a horizontal wet vent being prohibited.

If it is not part of a bathroom group, there is no wet venting.


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## plumbdrum

Again, different codes, in my code you have to roll your wet vent above the center line of the horizontal drain it serves











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## APP14

I wet vent bathroom groups all the time here in Michigan. I vent the washer box and laundry tub seperate. Depends on how the set up is. Underground pick up washer box and laundry tub before bathroom group. If I can't run the vent up and tye in I use a studor box and AAV. Same way for the kitchen where the dishwasher discharges into. I put an AAV under the sink. I've never had a problem. (Knock on wood ) I never looked into if an AAV can not be used on anything with a pump because Inspectors have no problem with it and pass everytime.


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## APP14

Except sewage electors. Atmospheric.


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## Best Darn Sewer

It is always so I interesting to read these discussions on wet venting being it isn't allowed here except in one case with minor over major like a lav tying into a toilet vent stack. Other than that, at the state board where we take our j-mans and masters exam they have signs everywhere saying no wet venting for the doll house project. Every fixture must have its own vent. I'm not sure why Texas is different other than we seem to be different than a lot of states in many areas beyond plumbing.


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## rjbphd

APP14 said:


> Except sewage electors. Atmospheric.


 You can use aav on sewage ejector.. u just gonna know how to do it correctly and understand the venting principle..


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## BC73RS

plumbdrum said:


> Out of curiosity , why can't you wet vent a 3" trap? I doesn't make sense.
> 
> Sent from my iPhone using PlumbingZone


Sorry for the confusion, we can wet vent a 3" trap.
But a 3" trap cannot be used as a wet vent, hope that makes sense.


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## plumbdrum

BC73RS said:


> Sorry for the confusion, we can wet vent a 3" trap. But a 3" trap cannot be used as a wet vent, hope that makes sense.


What if you had a 3" trap for a shower and wet vented a WC? It would be legal in my state, just throwing out another scenario

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## BC73RS

plumbdrum said:


> What if you had a 3" trap for a shower and wet vented a WC? It would be legal in my state, just throwing out another scenario
> 
> Sent from my iPhone using PlumbingZone


In our code a wet vented WC can only recieve 2 FU's max. per fixture. A 3" trap is 3 FU's.


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## plumbdrum

BC73RS said:


> In our code a wet vented WC can only recieve 2 FU's max. per fixture. A 3" trap is 3 FU's.


Got it, it always is interesting reading about different codes.

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## BC73RS

It's funny but true, each fixture tied into the wet vent portion can be max. 2 FU'S per fixture for a total load of 6 FU's... not including the WC.
So 3 2" traps can be tied in to the wet vented portion.


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## plumbdrum

BC73RS said:


> It's funny but true, each fixture tied into the wet vent portion can be max. 2 FU'S per fixture for a total load of 6 FU's... not including the WC. So 3 2" traps can be tied in to the wet vented portion.


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## plumbdrum

BC73RS said:


> It's funny but true, each fixture tied into the wet vent portion can be max. 2 FU'S per fixture for a total load of 6 FU's... not including the WC. So 3 2" traps can be tied in to the wet vented portion.


It's true for your code, the minimum size wet vent is 2" in my code, I could run. A 4" wet vent and pick up the fixture units allowed on 4" horizontal .

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## Chris3topher271

Going back to hypothetical, people are mentioning that the clothes washer's and kitchen sinks (exempt from horizontal wet venting) are suds producing and that's why they wouldn't do it. Bathtubs are considered suds producing as well so doesn't that nullify the argument? The only consistency I see is that the kitchen sink (with dishwasher) and ACW are discharging at a higher rate.

Ok so I finished writing the above and realized that the 2 fixtures (appliances) are ones that are run and left on. If they're basing the code on a low probability that all fixtures will discharge at once then that would make a certain amount of sense. Just thought I'd throw that out there.


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## BC73RS

As far as suds zones go I'll have to to say that the code was written for the type of laundry soap that was used back in the day in it's concentrated form. Bubble bath and dish soap didn't fall into that category as far as I know.


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## Cajunhiker

I looked all over our code book and don't see anything about soap "sud zones" regarding ACWs and K/S. So, assuming I have an ACW upstream that is independently vented through the roof, and all other fixtures (shower, lav, wc, k/s) downstream are independently vented (each trap has a vent), I shouldn't have to worry about "sud zones" from the upstream ACW because of the independent vents on each downstream trap. Yes or no?


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## Tommy plumber

Cajunhiker said:


> I looked all over our code book and don't see anything about soap "sud zones" regarding ACWs and K/S. So, assuming I have an ACW upstream that is independently vented through the roof, and all other fixtures (shower, lav, wc, k/s) downstream are independently vented (each trap has a vent), I shouldn't have to worry about "sud zones" from the upstream ACW because of the independent vents on each downstream trap. Yes or no?












When the automatic clothes washer discharges, it is supposed to tie into the drain downstream of the bathroom group if the bathroom group is a horizontal wet vent. Even though your bathroom fixtures are independently vented, I would not allow the ACW to drain upstream of the bathroom. I would tie the ACW into the drain downstream of the bathroom group.

But in LA, your code may allow the ACW to drain upsteam. The last thing you want is for suds to come up out of the overflow of the tub.


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