# Understanding Vent Plumbing



## remout (Sep 21, 2015)

I'm putting a bathroom in a 121 y/o Cottage with a raised foundation. The walls are solid wood, however one wall, I'm adding, will be typical 2 x 4 stud  construction. Below is a view from above depicting the bathroom fixtures and the stud wall.






Now a view from the side showing how I think the drain and vent plumbing can be run. Am I getting it right?   Thanks!


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## nealtw (Sep 21, 2015)

I think you need anther wall at the end of the tub, so you can run another vent up and tie it to the other one above. But Frodo should be alnog soon.


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## CallMeVilla (Sep 21, 2015)

Here is a good diagram of your situation (from the other side)  ....  you made a good try at it, BTW.  Notice the main vent stack is in the middle, not the side.  However, it can be relocated.  Notice the use of traps at each point.  This prevents sewer gasses from flowing back into the house.  Your drain lines should have a 1/8" per foot fall to facilitate water flow.  The sweep on the toilet is NOT a simple 90 degree sweep ... you want a sweep specifically for the toilet application.  Good luck, sounds like you are doing the right stuff.


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## remout (Sep 21, 2015)

Okay, Thanks! 
I can make that work and even better I'm beginning to understand it.


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## frodo (Sep 22, 2015)

the above drawing by Mr Villa is not code compliant


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## frodo (Sep 22, 2015)

.....................


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## remout (Sep 23, 2015)

"that fitting has to be below the T for the toilet".... got it, thanks!

I don't think this matters, but I've only got one wall that has room for plumbing. The other 3 are solid cypress barge board walls (121 y/o cottage)


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## nealtw (Sep 23, 2015)

That's why I said said you may need another wall at the end of the tub?


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## frodo (Sep 23, 2015)

tub vent...


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## frodo (Sep 23, 2015)

post, the wall layout for the floor.

all the walls in that general area.  looking for a wall within 5'  

what wall is the water for the valve going in?


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## remout (Sep 24, 2015)

Drat, I don't have an accessible wall within 5' of the tub. I didn't include it on this drawing but there is another door going from bathroom to utility room. Am I correct that every drain would have to be within 5' of the accessible wall? So in the case of the tub, the center of the tub would need to be within 5' of wall?


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## frodo (Sep 24, 2015)

you gotta have plumbing walls,


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## nealtw (Sep 24, 2015)

frodo said:


> you gotta have plumbing walls,



What's the deal when they do a loop under an island sink and vent back thru the floor, I've seen it but never really looked at it.


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## frodo (Sep 24, 2015)

its an island vent, still has to have a wall


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## slownsteady (Sep 24, 2015)

you could run your vent stack outside against the wall, wouldn't look pretty, but you could enclose it in a chase.


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## remout (Sep 28, 2015)

I spoke with our local building inspector and he recommended using 2" drain pipe from the p trap on the tub to the vent . He said 2" can span 8'


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## Snoonyb (Sep 29, 2015)

remout said:


> I spoke with our local building inspector and he recommended using 2" drain pipe from the p trap on the tub to the vent . He said 2" can span 8'



Another consideration is the architecture.

What are you using to connect the faucet through the floor, copper, brass, chrome pated or sleeved galvanized?

As an alternative you could run the vent in copper, exposed, coated, painted or raw and let the natural patina develop.


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## edlank (Oct 21, 2015)

Frodo, for my education, why does the T need to be below the T for the toilet?


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## frodo (Oct 23, 2015)

,,,,,,,,,,,,,,,,,,,,,,,


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## frodo (Oct 23, 2015)

nealtw said:


> What's the deal when they do a loop under an island sink and vent back thru the floor, I've seen it but never really looked at it.


\\\


the loop is for free flow of air.  i personally disagree with this method

i think it is over kill,  not needed

my theory is the foot vent is not needed, just the loop vent


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## nealtw (Oct 23, 2015)

frodo said:


> \\\
> 
> 
> the loop is for free flow of air.  i personally disagree with this method
> ...


Thanks:
Could that have been used here, if the loop was as high as the overflow behind the tub?


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## frodo (Oct 23, 2015)

I dont know, the code calls it a "special venting for island fixtures"

If I wanted to use it, I would make a call first,  ask the question, 

before installing.


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## remout (Nov 29, 2015)

Fellas, I passed my rough in inspection with flying colors. Thanks for all your help!


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