# Venting



## OldSchool

From a recent thread I find it interesting the logic behind some venting principles in different areas of North America…

One being 

*No horizontal vent below flood level rim…*

Exactly how are you guys getting around this on a bath tub or shower or floor drain

Even in the case where you were doing a lav or kitchen …. More or less you are implying that it has to go straight up until it passes the flood level rim…. or is there some maimum horizontal length...

I am assuming we all agree that all vents are tied in below the flood level rim of every fixture….

Up here we are allowed to vent horizontal below the flood level rim ... so just trying to figure your logic in the horizontal venting restriction

I have included some pics to describe what I am talking about.... a picture is worth a thousand words they say


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## Pipe Rat

Those all look good to me OS


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## U666A

Thanks OS for asking that question. I didn't want to for fear of looking stupid, I'm really good at that already, don't need any practice...lol.

I'll be curious to read the responses here as I have pondered these things through posts I have read recently.


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## OldSchool

Well it came up in the island sink thread

and somebody said you can't do this... here is the pic


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## SlickRick

The drawing of the sink would be against code here, due to the low dry vent. Bring the drain up beside the window, and arm over within the max allowable developed length.

On the floor drain, same thing, vent in wall, trap arm.

If the FD exceeded the max. trap arm length, then we would use a combination waste and vent, and size appropriately, such as in a restaurant.

If it has a lav., etc on the vent to wash out the low section, that would be acceptable


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## Pipe Rat

Well I cant say I agree with the island sink version. Here we would do a loop vent.


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## OldSchool

Pipe Rat said:


> Well I cant say I agree with the island sink version. Here we would do a loop vent.


Well if you agreed with drawing #1 and drawing #2 

Then it should be fine for drawing #3

That is why I posted drawing 1 and 2 first :laughing:

Drawing #3 is no different from drawing #2


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## greenscoutII

To answer your question, usually find a way to wet vent. For example, for a tub/shower a lot of times I can wet vent the whole bathroom group through the lav.

For floor drains, the easiest way is to employ a combination waste and vent. What we would do is run 3" (minimum 18", max 15') to a three inch P-trap. A 3X2 bushing is glued into the trap with a 2" stand pipe to the floor drain itself.

Personally, the best thing about plumbing in Pueblo county is that they will allow a horizontal vent below flood level rim provided that drainage fittings are used and it's pitched quarter bubble.


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## OldSchool

greenscoutII said:


> To answer your question, usually find a way to wet vent. For example, for a tub/shower a lot of times I can wet vent the whole bathroom group through the lav.
> 
> *For floor drains*, the easiest way is to employ a combination waste and vent. What we would do is run 3" (minimum 18", max 15') to a three inch P-trap. *A 3X2 bushing is glued into the trap with a 2" stand pipe to the floor drain itself.*
> 
> Personally, the best thing about plumbing in Pueblo county is that they will allow a horizontal vent below flood level rim provided that drainage fittings are used and it's pitched quarter bubble.


Why would you not just keep the Inlet top of the floor drain remain 3".... what purpose would reducing it to 2" serve.

We all know what a wet vent can do.... the question is the restriction on horizontal dry venting below the flood level rim

All we have here is DWV fittings.


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## Redwood

OldSchool said:


> Well it came up in the island sink thread
> 
> and somebody said you can't do this... here is the pic





OldSchool said:


> Well if you agreed with drawing #1 and drawing #2
> 
> Then it should be fine for drawing #3
> 
> That is why I posted drawing 1 and 2 first :laughing:
> 
> Drawing #3 is no different from drawing #2


Well not really...
The primary objection I can see is the length of the tailpiece down to the trap and the trap being under the floor.

The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...

But they are kinda weird there anyway kinda like you guys up north Old School....


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## OldSchool

Redwood said:


> Well not really...
> The primary objection I can see is the length of the tailpiece down to the trap and the trap being under the floor.
> 
> The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...
> 
> But they are kinda weird there anyway kinda like you guys up north Old School....


Maybe ... just maybe we are a little more advanced than most places :laughing:


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## greenscoutII

OldSchool said:


> Why would you not just keep the Inlet top of the floor drain remain 3".... what purpose would reducing it to 2" serve.


Honestly, I often wondered the same thing myself. Pikes Peak Regional Building Department insisted it be done that way, so I never really questioned it.


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## OldSchool

greenscoutII said:


> Honestly, I often wondered the same thing myself. Pikes Peak Regional Building Department insisted it be done that way, so I never really questioned it.


I would certainly question that..... I cant see any logical reason to do that


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## Redwood

OldSchool said:


> Maybe ... just maybe we are a little more advanced than most places :laughing:


Or maybe you just like increased noise of water falling in the drain and a chance to have more surface of the pipe above the water in the trap to give you a chance at having more odors from the drain...

I dunno but if its legal there and you like it then go for it...


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## OldSchool

Redwood said:


> Well not really...
> The primary objection I can see is the length of the tailpiece down to the trap and the trap being under the floor.
> 
> The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...
> 
> But they are kinda weird there anyway kinda like you guys up north Old School....


Okay RED answer this what is your max distance from the pic below


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## Redwood

That would be 24" which ain't gonna make it below the floor unless we are doing a custom dwarf home....


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## Pipe Rat

OldSchool said:


> Well if you agreed with drawing #1 and drawing #2
> 
> Then it should be fine for drawing #3
> 
> That is why I posted drawing 1 and 2 first :laughing:
> 
> Drawing #3 is no different from drawing #2


Not really OS. In drawings 1 and 2 the trap is near the fixture being served. I can't go along with the trap below the sink cabinet.


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## Epox

Vents can 45 horizontally below cl but not 90. Here anyway. I'm having a hard time knowing why you'd trap an island sink below floor anyway. And a loop vent would be in order as PR said.


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## OldSchool

Redwood said:


> That would be 24" which ain't gonna make it below the floor unless we are doing a custom dwarf home....


Here we are allowed 36"


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## OldSchool

mpsllc said:


> Vents can 45 horizontally below cl but not 90. Here anyway. I'm having a hard time knowing why you'd trap an island sink below floor anyway. And a loop vent would be in order as PR said.


All our dry vents have to be 45 deg higher than center line here on horizontal drain....

So as long as your TY is rolled 45 deg higher than center then it could be a 90 elbow on top of the TY running a dry vent horizontal with grade of coarse.


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## Mpls Jay

This may look old to *some* of you but..
From State of MN code...

Subp. 2. Vertical rise. Where vent pipes
connect to a horizontal soil or waste pipe, the
vent shall be taken off above the center line of
the pipe. The vent pipe shall rise vertically, or at
an angle not more than 45 degrees from the
vertical, to a point at least six inches above
flood-level rim of the fixture it is venting, before
offsetting horizontally or before connecting to
the branch vent.
Subp. 3. Height above fixtures. A
connection between a vent pipe and a vent stack
or stack-vent shall be made at least six inches
above the flood-level rim of the highest fixture
served by the vent. Horizontal vent pipes
forming branch vents, relief vents, or loop vents
shall be at least six inches above the flood-level
rim of the highest fixture served.


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## DUNBAR PLUMBING

Mpls Jay said:


> This may look old to *some* of you but..
> From State of MN code...
> 
> Subp. 2. Vertical rise. Where vent pipes
> connect to a horizontal soil or waste pipe, the
> vent shall be taken off above the center line of
> the pipe. The vent pipe shall rise vertically, or at
> an angle not more than 45 degrees from the
> vertical, to a point at least six inches above
> flood-level rim of the fixture it is venting, before
> offsetting horizontally or before connecting to
> the branch vent.
> Subp. 3. Height above fixtures. A
> connection between a vent pipe and a vent stack
> or stack-vent shall be made at least six inches
> above the flood-level rim of the highest fixture
> served by the vent. Horizontal vent pipes
> forming branch vents, relief vents, or loop vents
> shall be at least six inches above the flood-level
> rim of the highest fixture served.


 
^^^ 

Correct. Follows KY code to a tee. Has to be a 45 degree turn of direction or greater. 

Why? So solid waste slithers back out of the vent piping when the clog is removed from the system.

Otherwise, it sits in there and accumulates, sealing it off permanently in most cases.


6" above the flood level rim as we know once it's above that height (in a clogging scenario that you're guaranteed the sloping vents would take the waste away, in a drain type of slope design.

Can never see that happening but codes were designed because it happened one time or another.


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## gitnerdun

I can smell the nastiness coming from a 36" standpipe under the kitchen sink from here!


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## Will

OldSchool said:


> Exactly how are you guys getting around this on a bath tub or shower or floor drain



Every tub, or shower I do the same. I look a 90 up in the wall cavity, then "swing the trap" with a san tee in the direction I need it roughed in. The vent is vertical. 2" Trap Arm is under slab and so is P-Trap. Can go up to 6' from vent on 2". I think IPC 2009 lets you go 8'.


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## Will

here's two shower roughs. I don't don't how to do those iso drawlings on the computer so I'll just post the real thing.


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## OldSchool

gitnerdun said:


> I can smell the nastiness coming from a 36" standpipe under the kitchen sink from here!


There is no smell issue with the 36 inch stand pipe


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## OldSchool

Now I find this method that somebody posted really odd...

Now you guys are telling me this is considered a vent????


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## Pipe Rat

Yes OS that is a loop vent. Here it can only be used for island fixtures and vent must tie in a minimum of 5' downstream.


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## OldSchool

Pipe Rat said:


> Yes OS that is a loop vent. Here it can only be used for island fixtures and vent must tie in a minimum of 5' downstream.


So where does it get the air from???

More or less it is taking or trying to take air from the drain while it is in use.... very odd...

If they consider this a vent.... under your code.... and some how they figure this would work properly.... then this does call into question other venting practices....

That being said.... more or less this type of venting would work on every fixture according to their theory. If it works on that fixture it would work on others...


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## Pipe Rat

Its only allowed where no other option exist. If i'm not mistaken you have to upsize the drain line one size. I still prefer this over an AAV or a trap below the floor.


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## Will

It's only allowed for sinks or lavatories.


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## SlickRick

OldSchool said:


> So where does it get the air from???
> 
> More or less it is taking or trying to take air from the drain while it is in use.... very odd...
> 
> If they consider this a vent.... under your code.... and some how they figure this would work properly.... then this does call into question other venting practices....
> 
> That being said.... more or less this type of venting would work on every fixture according to their theory. If it works on that fixture it would work on others...


As long as the pipe is sized to allow air flow in the top section of the pipe and there is a source of air for the system, then yes it would work on any fixture.


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## Airgap

Will said:


> It's only allowed for sinks for lavatories.


That's not a lavatory....


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## OldSchool

Pipe Rat said:


> Its only allowed where no other option exist. If i'm not mistaken you have to upsize the drain line one size. I still prefer this over an AAV or a trap below the floor.


I am not a big Fan or user of AAV.... and still believe that a plumbing system should be completely installed....

We use to call those cheater vents along time ago..... at that time they were illegal...

Like any mechanical device it will fail eventually.... Then there is also the problem that at some point in time somebody will enclose the AAV in a wall or concealing it not allowing it to get any air...

So not a big fan of AAV


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## plbgbiz

delete...duplicate post.


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## OldSchool

Will said:


> It's only allowed for sinks for lavatories.


according to the information so far that picture would not be legal to your code..

according to one member the vent has to be tied 5 ft down the drain line 

also I see a horizontal vent tied into your loop vent .... now would that be legal


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## plbgbiz

Even if the inspectors would allow this here (and I don't think they would), I would not do it because of the smelly stand pipe.










Nothing allowed over 45deg here.


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## Will

Airgap said:


> That's not a lavatory....



meant to say sinks OR lavs


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## Pipe Rat

OldSchool said:


> according to the information so far that picture would not be legal to your code..
> 
> according to one member the vent has to be tied 5 ft down the drain line
> 
> also I see a horizontal vent tied into your loop vent .... now would that be legal


We never had the horizontal vent tied into the loop vent. Could be that way now I don't know. A new code has been adopted since I have had the need to use one and have not looked it up.


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## Will

OldSchool said:


> according to the information so far that picture would not be legal to your code..
> 
> according to one member the vent has to be tied 5 ft down the drain line
> 
> also I see a horizontal vent tied into your loop vent .... now would that be legal


It doesn't have to be 5'. At least not by IPC, locally it could be different. Hell you can even do a combination drain and vent for a kitchen sink with a 3" pipe and no vent.


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## OldSchool

Here is what I see wrong with the picture so far

according to your code


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## Will

What the picture doesn't show is a clean out on the vent in the wall to clear the line if a blockage occurs. To be honest I use a AAV:whistling2: on island vents most of the time. It's legal and works better than a loop vent.


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## Pipe Rat

Trust me Will, St louis county, Mo. has so many amendments I dont know why they even base it on a code. It would be simpler if they just wrote their own. :yes:


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## OldSchool

Will said:


> What the picture doesn't show is a clean out on the vent in the wall to clear the line if a blockage occurs. To be honest I use a AAV:whistling2: on island vents most of the time. It's legal and works better than a loop vent.


So now you are saying that a vent could be horizontal below the flood level as long as it has a clean out?


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## Epox

The last new house I done was a straw house. They stucco inside and out and is a lot of work. The ho's called me in to top-out after the dang house was all but completed but with a twist. The inside walls went up 8 feet. Ceilings were 12 ft. or so. Having to cut sheetrock and insulation to top-out was frustrating to say the least. Sorry to ramble but point is I called state inspector out as this was out of town, he actually allowed me to auto vent everything septs commodes that had full wall up to ceiling. What a mess.


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## SlickRick

IPC does not have the 5' rule. The picture would be a perfect example of a " Island vent" to code around here.


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## OldSchool

slickrick said:


> IPC does not have the 5' rule. The picture would be a perfect example of a " Island vent" to code around here.


well that would contradict what you were saying about horizontal vent below flood level rim


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## Will

OldSchool said:


> So now you are saying that a vent could be horizontal below the flood level as long as it has a clean out?


Yes it can. I never said it couldn't. It also _MUST RISE ABOVE THE BOTTOM OF THE FIXTURE BOWL. _That way if a stoppage occurs, water will show in the bowl before the vent.


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## Will

Pipe Rat said:


> Trust me Will, St louis county, Mo. has so many amendments I dont know why they even base it on a code. It would be simpler if they just wrote their own. :yes:



I believe you. OKC is the same way. I wish there was a national code like electricians have. Be alot less confusing.


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## grandpa

Kitchen window over sink is very common here. Typically, the drain trap arm is run horizontally inside the cabinets, to the left or right, where it enters the wall into a san tee and the vent goes straight up.

Most bathrooms are small enought that the trap arm for the tub or shower goes to the wall, enters a san tee and vent goes up.

What's the problem?


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## SlickRick

OldSchool said:


> well that would contradict what you were saying about horizontal vent below flood level rim


It dosen't contradict anything. An island vent is covered buy it's own section in the IPC. Section 913, "Island fixture venting".


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## plumbpro

Will said:


> It doesn't have to be 5'. At least not by IPC, locally it could be different. Hell you can even do a combination drain and vent for a kitchen sink with a 3" pipe and no vent.


There still has to be a vent somewhere in the combination waste and vent system. Like before it ties into a soil line. I will run a 3" under a kitchen or a lav. Kitchen if it is an island or bar, lav in a remodel. You are supposed to extend the 3" as high up in the cabinet as you can and terminate with a cap.


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## OldSchool

Will said:


> Yes it can. I never said it couldn't. It also _MUST RISE ABOVE THE BOTTOM OF THE FIXTURE BOWL. _That way if a stoppage occurs, water will show in the bowl before the vent.


That question or statement was directed to SlickRick

That horizontal dry venting was not approved below the flood level rim

yet the picture you submitted clearly shows a horizontal vent below the flood level rim....

Slick says now that the pic you submited would be approved


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## Will

plumbpro said:


> There still has to be a vent somewhere in the combination waste and vent system. Like before it ties into a soil line. I will run a 3" under a kitchen or a lav. Kitchen if it is an island or bar, lav in a remodel. You are supposed to extend the 3" as high up in the cabinet as you can and terminate with a cap.



What I don't get is IPC won't let combination drain and vent systems on kit sink with disposers, yet I see new construction plumbers all over installing them. Wonder if it is a OKC thing. You see it in Arkansas plumbpro?


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## plumbpro

Will said:


> What I don't get is IPC won't let combination drain and vent systems on kit sink with disposers, yet I see new construction plumbers all over installing them. Wonder if it is a OKC thing. You see it in Arkansas plumbpro?


Yes, all the time. Here it is legal to do so. Here you could run a 2 comp sink with disposal into a single 1 1/2" arm, using an end or center waste. I think that is a bad idea, but it is legal here.


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## SlickRick

I am not saying that any code is better than another. These arrangements for different systems are submitted by members of various code bodies, and if enough members vote that they see the variation as sound plumbing principles, they become part of the code. As a member of the SBCCI code body while I was an inspector, we were sent a book to review, with ideas that had been submitted , we checked yes or no as to whether we felt it needed to be added or removed in the next code addition. Most of these concepts are submitted by members that are plumbers like us and not engineers. Some ideas are sound, some are out there. The book is thick with ideas.


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## plumbpro

none of the original pictures posted would be allowed here. The island sink would have been run in 3" with the dry vent coming off of the top and straight up the wall, same with a floor drain. The offset would have had to be 6" above flood level to pass inspection. A wet vent run under a slab can be run horizontal as long as it is sized properly. I always make the wet vent section under a slab 3", which is oversizing in a lot of cases, but I feel good about it that way.


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## a22ozbeer

Will said:


> What I don't get is IPC won't let combination drain and vent systems on kit sink with disposers, yet I see new construction plumbers all over installing them. Wonder if it is a OKC thing. You see it in Arkansas plumbpro?


In this case, I call it "island venting" and so does every inspector here in MI. And as far as distance from vent, you would adopt the distance from trap to vent table whether it be wet or vertically dry. If you island vent a kitchen sink with 3" through the cabinet then the distance would have to be no more then 12' resi. or 10' commercial. No loop, no horizontial dry vent, just a cleanout on top. This is IPC rules.


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## Mpls Jay

Missing from this is a clean out on the wall vent side.I've bumped into more that a few that gurgle because that vent is plugged and the rockers and or carpenters covered that c/o .


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## 6th Density

Great debate guys. I'm with will, a22ozbeer, and plumbpro. 2" island sink is permitted but why not skip the aav and go 3"? Plus you can still put a garbage disposal on 3"! AHJ here makes for tubs and showers having to come off a san tee as a trap arm "underground" with a vent out the top of the san tee "in wall"! You might ask why? Think about the sorry service tech who has to clean out the system. Wouldn't you want this customer you're building the house for also want you as his go-to service man!! Of all these systems which ones are the easiest to clean out?

edit: which ones are the easiest to install!!


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## shakeyglenn68

Will said:


> What I don't get is IPC won't let combination drain and vent systems on kit sink with disposers, yet I see new construction plumbers all over installing them. Wonder if it is a OKC thing. You see it in Arkansas plumbpro?


 I've seen and done it with 3" if the K/s is at an outside wall you put in a 3x2 combe putting the 2" out the wall for a cleanout. run the 3" up to a 3x2 stack then place a 3x2 bush w/aav. If the K/s isnt at the outside wall you lose the 3x2 bush and put a 3" street 90 with a 3" female w/cleanout cap. Works in most of Oklahoma (sometimes passes Norman depends on the Inspectors mood). In norman you absolutly can not offset before the FLR with anything greater than a 22. Have personial watched seasoned plumbers bang heads against the 2x4's when inspectors wipe out the tape measure and state, "Your 1/2" below FLR redo it!" The loops/s-traps are not allowed in OKC, Norman, Edmond, Stillwater, El Reno, and Shawnee. You sometimes can sneak it by the smaller town inspectors. Norman here in Ok, is the strictest :furious: of all the state.


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## plumber666

OldSchool said:


> Here we are allowed 36"


Pretty sure our codes are the same, it's 1200mm in BC (48")

For your vent under the window, rough the drain in off to the side of the window and have a trap arm in the wall. Tubs are almost always wet vented.


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## ianclapham

could you not use one of these









http://www.mcalpineplumbing.com/silenttraps.asp

save venting


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## plumber p

Redwood-- The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...

This is news to me!


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## SlickRick

ianclapham said:


> could you not use one of these
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> http://www.mcalpineplumbing.com/silenttraps.asp
> 
> save venting


 
I have used some similar elsewhere, but I don't see necessary code approvals for use in the US or Canada on their website. CSA,UPC,IPC etc.


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## Redwood

plumber p said:


> Redwood-- The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...
> 
> This is news to me!


Why is that news to you?

Does your code allow it?

What is your code?


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## 6th Density

plumber666 said:


> Pretty sure our codes are the same, it's 1200mm in BC (48")
> 
> For your vent under the window, rough the drain in off to the side of the window and have a trap arm in the wall. Tubs are almost always wet vented.



But that's one of the main reasons behind the idea of island venting. 

If a framer has a code to follow on how to build a window cripple to strengthen the insertion of them, what give us the right to notch or cut out 60% to 75% of their strength so we can put a drain pipe through it? Just island vent it!!!


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## Eric

I never drill an exterior stud or "load bearing" stud for a drain. Kitchen sink on an outside wall, whatever side the dishwasher is on, the kitchen drain is on the opposite side of the window over the sink IN THE WALL,

Not thru the floor of the cabinet. Sanitary tee at about 15" above the rough floor, turned out at a 45° angle roughed out of the wall, a 45° gets you back parallel to the outside wall and thru the sink base cabinet. No studs drilled. Yeah it's exposed in the cabinet next to the sink base cabinet but the vent is vertical. 

Vent continues up along side the window and can not go flat until 6" above flood level rim of kitchen sink. 

Tub drains get roughed horizontally under the back wall of the tub, vent is vertical in the wall behind the tub, and a long sweep 90 thru the joist (at the correct height) to the trap. 

Our code doesn't care where the trap is above the floor or below, but the max length from bottom of the fixture to the trap is 24" so that is the boss. 
MA code.


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## RW Plumbing

plumber p said:


> Redwood-- The only code I know of where something remotely similar to this is the Wisconsin State Plumbing Code that allows a trap under the floor on pedestal lav sinks...
> 
> This is news to me!


 Yeah we get 60" from fixture outlet to trap wier for a pedistal here. I've NEVER seen one done like that though.


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## RW Plumbing

ianclapham said:


> could you not use one of these
> 
> 
> 
> 
> 
> 
> 
> 
> 
> http://www.mcalpineplumbing.com/silenttraps.asp
> 
> save venting


That's a mechanical trap. Those are a no go here, fall under the same rule as a drum trap.


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## Fredsait

*venting...*

Drawing #3 is definetly illegal in Canada....you do a proper island vent (or loop vent as it is called the states).
Its illegal for several reasons....some of which are...the fixture outlet pipe may be too long....900mm in Alberta...1200 mm nationally. Even if it isn't too long, it will end up smelling from waste that adheres to the inside of the fixture outlet pipe which is before the sealed Ptrap.

Drawings #1 and #2 are fine if you install cleanouts on the horizontal vent which is below flood level rim.

cheers...Fred


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## PLUMBER_BILL

*A service call a long time ago.*

The call was for a kitchen sink that only drained half way ???

Yep that was the call and when I got there that is what it did, took the water away until it was 1/2 full or some might say 1/2 empty.

Now while it was draining it worked fine. Sink was centered on a outside wall under a window. I was baffeld, finally I filled the sink with hot water to the flood level, pulled the stoppers and went pipe feeling. What I felt was no change in temperature in the drain, but all of a sudden the vent from the laundry tub below got hot. Yep the installing contractor broke the vent below the window, went horizontal to the existing vent from the laundry in the basement and tied in the kitchen sink.
Ok the water could not run down the drain it was blocked. It was draining through the vent, when the water level got below the invert on the vent all draining would stop. I only saw it once but this topic reminded me of the situation.


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## OldSchool

Fredsait said:


> Drawing #3 is definetly illegal in Canada....you do a proper island vent (or loop vent as it is called the states).
> Its illegal for several reasons....some of which are...the fixture outlet pipe may be too long....900mm in Alberta...1200 mm nationally. Even if it isn't too long, it will end up smelling from waste that adheres to the inside of the fixture outlet pipe which is before the sealed Ptrap.
> 
> Drawings #1 and #2 are fine if you install cleanouts on the horizontal vent which is below flood level rim.
> 
> cheers...Fred


 
If the plumbing code allows for either 3 or 4 ft of pipe ..... then it would be legal regardless what anybodies feelings are or their opinion is about potential smell.

So to say that this would be illegal would be false... as long as it was with in the code...like anything else.


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