# Toilet drain, slope, vertical, then slope?



## mikegp (Jul 17, 2011)

That should be fine. It's done all of the time. Are you using the stack as the vent?


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## garwein (Feb 23, 2015)

mikegp said:


> That should be fine. It's done all of the time. Are you using the stack as the vent?


Yes, the stack goes straight up and is vented out the side of the house, above a lower level roof. 

What if I went 45 degree instead of vertical for the short section that has to go under the joist?


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## HvacSteve (Sep 4, 2017)

45s would probably be better. Less chance of clogging.


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## mikegp (Jul 17, 2011)

Is this getting inspected? I think 8ft is greater than the allowable distance from the toilet to the vent.


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## MTN REMODEL LLC (Sep 11, 2010)

I think you want to wait for our plumbers to explain trap arm distances and horizontal run/slope.


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## Nealtw (Jun 22, 2017)

MTN REMODEL LLC said:


> I think you want to wait for our plumbers to explain trap arm distances and horizontal run/slope.


I think 10 ft for 4" pipe. not sure about the drop in the center.


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## ct18 (Sep 20, 2012)

use 45° offsets.


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## garwein (Feb 23, 2015)

mikegp said:


> Is this getting inspected? I think 8ft is greater than the allowable distance from the toilet to the vent.


It's not getting inspected. I think the distance will probably be a total of 7ft, including the vertical or 45 degree drop, whichever I end up doing.


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## MTN REMODEL LLC (Sep 11, 2010)

MTN REMODEL LLC said:


> I think you want to wait for our plumbers to explain trap arm distances and horizontal run/slope.


THIS IS FROM A GC... I'm not a plumber.... but...

Normally, a trap arm is governed by a 1/4 slope before hitting it's vent.... and the length of that run is governed by the pipe size (which I think varies by UPC and IRC codes.

However, I am not sure of, and confused, in regard to a toilet... which to a limited sense (in time) has a self restoring trap.

Hence, I would wait for one of our professionals (whether you are under permit or not)

Just a personal opinion...:wink2:

Good luck


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## Ghostmaker (Mar 2, 2013)

New York I can't help.


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## 2x_Tom (Dec 14, 2015)

That wouldn't fly around here. Looks like about 22' of pipe to the vent to me. 8' horizonally, 1' vertically plus 2 90s (+6' per 90). I'm sure there's a way to cut in a vent and run it back to the stack up high. AAV's are another option.


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## TheEplumber (Jul 20, 2010)

MTN REMODEL LLC said:


> I think you want to wait for our plumbers to explain trap arm distances and horizontal run/slope.


UPC is 3"= 6' arm. That's from the flange to the tee. 4" is 10ft

The offset wouldn't fly


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## garwein (Feb 23, 2015)

TheEplumber said:


> UPC is 3"= 6' arm. That's from the flange to the tee. 4" is 10ft
> 
> The offset wouldn't fly


I'm using 4" all the way. 

I'm confused, so you guys are saying a 90 elbow adds 6 virtual feet to the overall length for venting purposes.

What about a diagonal with two 45s, would that be any different?


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## 2x_Tom (Dec 14, 2015)

A 45 would be better but but you still won't have a proper vent. Will it work? Maybe. Just get a real vent or even an aav up.


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## TheEplumber (Jul 20, 2010)

garwein said:


> I'm using 4" all the way.
> 
> I'm confused, so you guys are saying a 90 elbow adds 6 virtual feet to the overall length for venting purposes.
> 
> What about a diagonal with two 45s, would that be any different?


UPC code does not recognize pipe length allowances for fitting- yours might.

45's are the preferred flavor for making offsets though


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## garwein (Feb 23, 2015)

2x_Tom said:


> A 45 would be better but but you still won't have a proper vent. Will it work? Maybe. Just get a real vent or even an aav up.


But isn't my 4" vent and stack 7 feet away a proper vent and within the 10ft distance for 4"? Unless elbows add virtual distance?


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## MTN REMODEL LLC (Sep 11, 2010)

I' m not a pumber.... hope we can get some clarrification here....

But does not a trap arm... (distance between the trap weir and the vent) have to travel at a 1/4 slope with the distance limited by the size of the pipe. Basically to keep the trap arm breathing and prevent siphoning)

Your vertical drop in the trap arm (whether at 45 or 90) does not meet any code does it. 

Again... maybe there is a provision for a toilet with a self filling trap (to a certain degree).

I'm probably wrong...just curious for a clear explanation.


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## Nealtw (Jun 22, 2017)

The size of the pipe and the proper slope does not allow water to fill so height to stop air flow. 
http://inspectapedia.com/plumbing/Plumbing_Vent_Noise.php


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## 123pugsy (Oct 6, 2012)

Could a parallel vent tube above the drain pipe allow it to breathe?

If the pipe gets full at the first 45, air could still pull from this link pipe.

Just a thought.

Personally though, being 4" and no inspection, I'd just do it with the 45's and forget about it.


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