need some advice on plumbing drain / vent

[jakester]

here are 2 pictures of the drain pipe for my washer and on the other side of the wall is the bathroom sink with a P trap. I don't know much about plumbing but I don't think this is set up right. I need to redo this and add ventilation. I was thinking about putting in a air admittance valve as vent since I don't have a way to run piping to the main vent stacks. Any thoughts on what would be the right way to redo this?

 

[frodo]

if it were me, i would cut the wood away from the 2'' pipe coming out of the concrete

cut that pipe off 1 1/2'' above the floor start as low as you can,,so that the ptrap for the washer is as low as you can get it

 

[jakester]

Shouldn't the vent go after the P trap?

 

[jakester]

also what is the straight line all the way on the left?

 

[frodo]

Shouldn't the vent go after the P trap?

the vent protects the seal of the trap,due to negative pressure in the system.

if it were on the other side of the trap, a negative pressure situation could cause the trap to back siphon.


line to the left..nothing,,,looked like what it is not,,disregard

 

[jakester]

And what is the purpose off using 1 1/2" and 2" pipe? Can't it all be 2" or is 2" for drain and 1 1/2" for vent? Also I take it that the Air Admittance valve would go on top of the middle pipe right?

 

[jakester]

I do apologize for all of the questions - I like to do things myself as much as I can but when it comes to plumbing I don't know much but really like to learn for myself.

 

[frodo]

drain needs to be 2'' you can use 2'' instead of 1 1/2. its a cost thing, we run vents in 11/2 instead of 2 when we can to save a buck

 

[jakester]

What do you mean by aff? avi you mean aav? or what does avi mean?

Thank you very much! Your help is GREATLY APPRECIATED!!!

 

[frodo]

auto air vent, above finish floor

 

[jakester]

in your professional opinion what are you thoughts avi / aav?

 

[frodo]

I do not like them. in my opinion. if you add a vent. do not be lazy or cheap and use a auto vent

run the vent to another vent or out the roof.

auto vents have a rubber diaphragm, over time, rubber WILL fail and the damn thing WILL leak sewer gas into your home

causing a unsanitary condition and a safety issue due to flamable gass pooling in pockets.

BUTT, some idiot on the hill, got paid by a lobbyist to put the stamp of approval on them.

they are not legal every where. if you use one you need to call your plumber inspector to see if they can be used.


when dealing with the public, i do not mention them, i just run a vent the way it is SUPPOSED to be run.


that is my unbiased nonpartisian answer

 

[jakester]

I appreciate the honest answer and that is what I was looking for. I know the real vent is the way to go but where this is (basement) it will be very hard to run a vent pipe but I will look into that for sure.

 

[jakester]

Does the drain / p trap from the bathroom have to be 2 inches as well?

 

[jakester]

this is the where the original picture meets on the other side of the bathroom wall.

 

[phishfood]

1 1/2" will be fine for that.

 

[frodo]

I appreciate the honest answer and that is what I was looking for. I know the real vent is the way to go but where this is (basement) it will be very hard to run a vent pipe but I will look into that for sure.

I have plumbed plenty of homes that had a basement.

this is my "formula" for hiding a vent.

first i try and find a pantry cabinet. pull the shelves out and run the vent in the back corner, exposed. put your capt crunch in front of it. never know its is their.
2nd. a closet, again, back corner
3rd behind the fridge
4th behind a bathroom door
5th towel cabinet in the bathrooom. back corner
plenty of places to run a vent with out tearing into a wall

 

[jakester]

So if my sink p trap / drain is 1 1/2" going to the main drain which needs to be 2", where do i put the adapter from 1 1/2" to 2"?

 

[frodo]

look at my drawing post #2 that tee needs to have an 1 1/2 outlet.

i drew it as a 2 x 1 1/2 x 1 1/2 tee,,,you want to run everything in 2''

thats ok go ahead

the tee would need to be a 2 x 2 x 1 1/2

 

[jakester]

Gotcha. I don't need to run everything in 2", I just wanted to make sure I understood where you need to use 1 1/2" and where you must use 2".