[shelbyc]

I have read with interest some of the questions on AAV vents for sinks/tubs. I have a problem in that I have a relatively new home 3 yrs. I do have stack vents but apparently not for the sinks. Other items toilets, tubs, kitchen and washer areas work fine. It is my two bathroom sinks that do not. There is no air vent in the new sinks I put in (like little holes in some old type) at any rate the sinks drain erratically or very slow and gurgle. I am wondering if I can install an AAV in the cabinet under the sink. I know I might have to replace them in the future but it is just a matter of opening the cabinet door and r&R them. My question is I want to do it right in one bathroom I have a double sink that I can put on the horizontal pipe between the two sinks. In the second bathroom there is only one sink but limited space and the only place to put one is to come out of the p trap ---extend the vertical pipe up past the bowl of the sink (under the counter) and then the horizontal pipe to the wall would T off into the wall about 5 inches below the AAV. Will this work??

[ballengerb1]

Lets first talk a bit about the missing vent stacks. They are inside the wall so are you certain they do not exist? A 3 year old home woild have had to pass a plumbing inspection.

[massplumber2008]

Hi all:

Ballenger's correct here... ;) I'm also betting that the vents for the sink are inside the wall.

My guess here is that those sinks you installed without the overflow hole are causing the issue. We are starting to see this a lot lately.

Most likely what you need to do is remove the old pop-up assembly and purchase and install a new vessel sink pop-up assembly... see image. The best type is the flip top(1st pic.), but mushroom (or umbrella) type (2nd pic.) also works fine. I don't like the grid strainer (last pic.) for this application as I just don't think it allows enough air to mix with the waste at the flat strainer.

I would recommend trying it at one sink and see if it makes a difference... pretty sure it will. These are available at all home improvement stores today.

One quick test for this is to fill the sink 1/2 way and then start to drain the sink but insert a large straw 1/2 way into the drain pop up... see if that improves drainage... let me know.. OK? If it does, you know how to proceed... ;)

Let us know if you want to discuss more...

MARK

PS: The new vessel sink pop up will be installed and the old pop up rod will just stay as a decoration (non-functioning).

[shelbyc]

Thanks for the quick responses fellas. I know the stack vents are in the wall but down stream from the toilets I can see them from the crawl space below (the plumbing is exposed down there) also we live in the county where there are no building codes (3rd class county). I will try the straw! What does that mean if it works and should I try installing the items you mentioned before installing the aav? Thanks for your patience

[shelbyc]

Once again don't mean to sound ignorant but I am!!

Shelby

[massplumber2008]

If it works then the drain is starving for air... could mean you need an AAV or you need to install one of the vessel sink pop ups I posted.

Let me know if sink drains better and if possible look into the wall under the sink... is the pipe going into the wall connecting into a 90 degree fitting (looks down to below) or is it a TEE fitting..? Peek around the pipe just as it enters the wall. You may even need to open up the plaster a bit.

If you have a TEE fitting present then the vent is present already and you will want to install the vessel sink pop up. If a 90 degree fitting is present then the sink is unvented and you will install the AAV you presented originally.

Try the straw test, check the fittings just as the pipe goes into the wall... let us know.


MARK

[ballengerb1]

Shelby, as long as you are trying to learn a bit about plumbing you should know there is a difference between a vent stack and a stack vent. I think we are trying to figure out if you have a vent stack.