# 1.5" vent for toilet with 3" drain?



## GBrackins (Apr 26, 2012)

I'm not a plumber so I can't help you out on this, but you do know that a water closet and toilet are the same thing right?


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## fulmar2 (Oct 31, 2012)

Thanks Gary - yes, I do know that it's the same; I have changed the wording of my question to reflect that.


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## Beepster (Oct 19, 2009)

I do not believe you can drop more than an inch for any items being vented.

When in doubt, give a call to your local building inspector.

B


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## TheEplumber (Jul 20, 2010)

You need a 2" vent as the foot note says and it needs to be within 6' of the flange. This is the way UPC has read since at least the mid 80's

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## fulmar2 (Oct 31, 2012)

TheEplumber said:


> You need a 2" vent as the foot note says and it needs to be within 6' of the flange. This is the way UPC has read since at least the mid 80's


Thanks, Eplumber. I wasn't sure that the footnote actually said that you needed a 2" vent. But if that is truly the case, is there any way that I can state that the 2" vent for the wet bar is my toilet vent? How about horizontal wet venting? The drain for the tub shower is 2", and the inspector suggested looking into horizontal wet venting rules. I didn't completely understand them, which is why I posted here: in the hope that someone could help me find a solution that does not require tearing up the concrete again.


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## TheEplumber (Jul 20, 2010)

Unfortunately I'm viewing this on my phone so the images are not clear enough. Give me a few hours till I get to a computer or I kill some zombies- which comes first 

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## ben's plumbing (Oct 6, 2011)

no disrespect but ...you can tell the inspector anything you want.....to get it to past.....but if its not plumbed right ..you will have problems down the road.. you should have 2" min vent size on water closet....wet venting some areas permit it ..some don't .....I personally don't like wet venting......your concrete is open all you have to do is cut in a new fitting with 2" instead if 1 1/2...now the time to make it right...ben sr


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## fulmar2 (Oct 31, 2012)

Hi ben's plumbing - no disrespect taken; thank you for taking the time to reply. I should have made it more clear that the concrete has already been poured. If it were open, I would have just changed the fitting - that would be pretty simple! 

I have read in a number of places that this vent will work, and I too believe that it will. For example, in the IPC, no vent is required at all for water closets (see figure 906.1). 

My challenge is this: Even if my system will work perfectly, I still need to conform to the 2010 UPC. I know from other trades that there is more than one way to skin a cat - and it is my hope that someone will look at my pictures, and make an observation that allows my installation to conform to the code. I hope that makes sense. Thanks!


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## ben's plumbing (Oct 6, 2011)

off the record..it will work....on the record it won't pass code..my bad thougth concrete was open......I really think you need to take the inspector to dinner get him drunk have him sign off and give you the inspection sticker:laughing::laughing:....just kidding....maybe ask him what he thinks is needed to get you through this.. ..does he seem reasonable....


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## DannyT (Mar 23, 2011)

in western ny the vent had to be 1/2 the diameter of the drain it served minimum. if you ran 4 inch for the toilet it had to be 2 inch, for 3 inch 1-1/2 was minimum. in the OP case he has vents all over the place. i would be interested in seeing a drawing of how the underground piping is actually run, couldn't really tell where everything tied in looking at the picture.


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## TheEplumber (Jul 20, 2010)

Your worst case scenario is to chip out the concrete and replace the 3x1.5 combo and 3" 90.
I work off an older UPC and horizontal wet venting is not allowed so I can't address the latest UPC horz. vent regs. But what you have now would not pass my inspectors. Will it work? Yes. Is it per UPC? No. Will your inspector let it slid? Maybe- if he is a plumber and not just a book smart inspector.
BTW I gotta ask- did you wrap the pipes with 3M tape? Looks like it. I'm curious as to why


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## fulmar2 (Oct 31, 2012)

DannyT said:


> in western ny the vent had to be 1/2 the diameter of the drain it served minimum. if you ran 4 inch for the toilet it had to be 2 inch, for 3 inch 1-1/2 was minimum.


DannyT - Thank you for your reply. This is my interpretation of the UPC as well. No where does the UPC explicitly say that you need a 2" vent. Unfortunately, all that matters is my inspector's interpretation of the code - so I need a workaround. I am wondering if the 2" vertical pipe for the wet bar could be considered the vent for the toilet. It is less than 6' away, and if I understand the code correctly, toilets HAVE to use horizontal wet venting to at least some degree due to the fact that the trap is in the toilet. I need a way to explain this "alternative" way of looking at it to my inspector. Another alternative would be to use the 2" pipe for the laundry. This one is downstream from the toilet.

@TheEPlumber - I did wrap the pipes in tape, as I thought it was necessary for pipes underground. It was some thick black tape with the UPC shield on it...


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## TheEplumber (Jul 20, 2010)

fulmar2 said:


> DannyT - Thank you for your reply. This is my interpretation of the UPC as well. No where does the UPC explicitly say that you need a 2" vent. Unfortunately, all that matters is my inspector's interpretation of the code - so I need a workaround.


Table7-5, footnote 3 states "Except six unit traps or water closets"
I have worked the UPC for more then 20 yrs. Always had to have a 2" vent for a toilet. You can count a WC as 3 FU when calculating total load on the common vent stack but it still needs to be minimum 2".


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## Alan (Apr 12, 2006)

TheEplumber said:


> You need a 2" vent as the foot note says and it needs to be within 6' of the flange. This is the way UPC has read since at least the mid 80's


I just looked all over, and I can't find it. I know it says it (or at least used to) but my 2008 Oregon Plumbing Specialty Code, does not say that on either of the tables that I can see.

Plz tell me where you see it?

TYIA.


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## Alan (Apr 12, 2006)

I need to read the entire thread before I reply.


I see that now, but the footnote in my book is referencing the 16 FU on the 2" vent column.


Maybe my interpretation is all effed up. 

At any rate, I know a 2" vent IS DEFINITELY required for a toilet. You are in trouble.


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## Alan (Apr 12, 2006)

TheEplumber said:


> Your worst case scenario is to chip out the concrete and replace the 3x1.5 combo and 3" 90.
> I work off an older UPC and horizontal wet venting is not allowed so I can't address the latest UPC horz. vent regs. But what you have now would not pass my inspectors. Will it work? Yes. Is it per UPC? No. Will your inspector let it slid? Maybe- if he is a plumber and not just a book smart inspector.
> BTW I gotta ask- *did you wrap the pipes with 3M tape? Looks like it. I'm curious as to why*


Nice catch. I would hate to be the guy cutting a fitting into that later on. 


In regards to horizontal wet venting : I've never done it, or had a situation where it will "fit", or even NEED to use it. Conventional systems always seem to prevail.

At any rate, based on the way it was explained to me, his would not work under the horizontal wet venting rule anyway.


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## TheEplumber (Jul 20, 2010)

TheEplumber said:


> Table7-5, footnote 3 states "Except six unit traps or water closets"
> I have worked the UPC for more then 20 yrs. Always had to have a 2" vent for a toilet. You can count a WC as 3 FU when calculating total load on the common vent stack but it still needs to be minimum 2".


This is from my '03 UPC which Idaho uses- we have some state revisions but this is not one of them.


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## fulmar2 (Oct 31, 2012)

Alan said:


> Nice catch. I would hate to be the guy cutting a fitting into that later on.
> 
> 
> In regards to horizontal wet venting : I've never done it, or had a situation where it will "fit", or even NEED to use it. Conventional systems always seem to prevail.
> ...


Alan - thanks for your reply - even though it is not what I wanted to hear (the point about the tape did not occur to me.  

Anyway, I appreciate that you thought about alternative solutions - even though you don't see any. One concern I had about using the pipe that comes up for the laundry is that it is not part of the "bathroom group" - same for the wet bar. Both are 2". I am assuming that when you say this would not work under the horizontal wet venting rule, that is what you mean.


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## jaydevries (Jan 29, 2012)

i have seen disputes like this go to court just to prove a point. the plumbing code is to protect the welfare of people and to make sure it is functional. so how is it that upc and ipc are so different but still work and are safe just like the size vent needed on a toilet. and in all cases here it was ruled by a judge if it does not affect the welfare and function it is fine and must be past. just like how everything in California can cause cancer. but is it worth the dispute that is a personal decision. it hall comes done to the opinion of the one who has the loudest voice and money :thumbup:


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## Alan (Apr 12, 2006)

jaydevries said:


> i have seen disputes like this go to court just to prove a point. the plumbing code is to protect the welfare of people and to make sure it is functional. so how is it that upc and ipc are so different but still work and are safe just like the size vent needed on a toilet. and in all cases here it was ruled by a judge if it does not affect the welfare and function it is fine and must be past. just like how everything in California can cause cancer. but is it worth the dispute that is a personal decision. it hall comes done to the opinion of the one who has the loudest voice and money :thumbup:


And in this case, changing a fitting will save a whole lot of people a lot of time, energy, and money.


To the OP : Did you put a 3x2 fitting with a bushing in it, or did you use a 3x1.5" fitting?


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## fulmar2 (Oct 31, 2012)

Alan said:


> And in this case, changing a fitting will save a whole lot of people a lot of time, energy, and money.
> 
> 
> To the OP : Did you put a 3x2 fitting with a bushing in it, or did you use a 3x1.5" fitting?


It's a 3x1.5"

I think that there is some ambiguity in the code, but I don't plan to take this to court. 

The reason I posted here is that I hoped someone could look at my pictures and see if there is an alternative way to "make it fit." 

I think everyone agrees that my setup will work, and it will be safe. If a 1.5" vent can handle 8DFUs, and I'm going to be using a 1.28GPF toilet (the DFUs for which aren't even in the table, but it is probably less than the 3DFUs of a 1.6GPF toilet) - then it seems we have a lot of lee-way - especially since where it stubs out of the concrete, I can easily put a reducing coupler so the vertical part of the vent will be 2". Furthermore, all of my fixtures are independently vented, with the correct size vent or larger.

All I need need to do here is make it work "on paper." If that can be done by horizontal wet venting (I have those two 2" pipes coming up - one for the washer, one for the wet bar, both within 6'), then great. If there is no way to make it work on paper, then so be it.

I believe that making it work on paper will be better, and less work for everyone. That fitting is under a wall - so I'd have to tear down the wall, cut out the concrete, and unwrap that tape. Then, I put it all back together with no-hubs and a new, separate chunk of concrete... Am I really making it better? Is a no-hub as good as a glue fitting? Are separate pieces of concrete really as good as one? 

No one has mentioned an alternative solution, so I'm thinking I will probably have to dig it up; nevertheless, I'm going to hold out a few more days in case someone here can see something that I've missed.

Thanks again to everyone who has taken the time to reply - I really appreciate it!! :thumbup:


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## Alan (Apr 12, 2006)

fulmar2 said:


> I think everyone agrees that my setup will work, and it will be safe. If a 1.5" vent can handle 8DFUs, and I'm going to be using a 1.28GPF toilet (the DFUs for which aren't even in the table, but it is probably less than the 3DFUs of a 1.6GPF toilet)


I agree that it will work as well, but again, it doesn't matter what I think.


Table 7-4 talks about what you are discussing here. They rate an unlisted fixture based on GPM discharge capacity. (not that your toilet will tell you what that is anyway)


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## jaydevries (Jan 29, 2012)

ok here is what you could do is cut 1 1/2 pipe flush with bottom plate cut bottom plate around pipe with hole saw just big enough for a 2 " coupling then glue 1 1/2" reducer bushing inside of 2" coupling then glue in to 1 1/2 " pipe then it just looks like you extended the 2" vent after concrete was poured :whistling2:


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## Alan (Apr 12, 2006)

jaydevries said:


> ok here is what you could do is cut 1 1/2 pipe flush with bottom plate cut bottom plate around pipe with hole saw just big enough for a 2 " coupling then glue 1 1/2" reducer bushing inside of 2" coupling then glue in to 1 1/2 " pipe then it just looks like you extended the 2" vent after concrete was poured :whistling2:


I had already thought of this, but it's cheating.

That will work, but usually the inspector wants to see what is under the concrete. If you have to show him pictures, he'll know that it's 1.5"


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