plubing question : drain vents?

[Randy R]

I had new plumbing for a 3 tub sink, etc. at my store. When the inspector came he told the plumber that he had to add a vent between the sink drain and the new drain line. Well he added the vent, which opens into the back room where the sinks are. I didn't think anything about it at the time, but shouldn't the vent go out the roof or something?

Every once in a while we will get a smell like sewer gas in the back room. Usually it goes away if I dump some bleach or something down the sink. I don't know if just running a bunch of water down the sink does the same thing, I just thought of this. The washrooms where I used to work would smell like this sometimes, and someone told me it was because the trap in the floor drain was dry and you just had to pour some water down the drain.

Randy R

[buffalobill]

see:

pdf for surevent:

[Edwin Pawlowski]

Most vents do go out but there is a vent that opens only when the water is running. I don't know about your codes, some places allow them, some don't. Going up through the roof probably would have cost you hundreds of dollars more for the job. May have even been impossible, depending construction and location.

[Joseph Meehan]

It sounds like he used a vacuum breaker and it is not properly functioning. Here is an example

[Randy R]

Thanks. There is no fixture like this on the end of the pipe. It is just a

2" pvc pipe coming out of the floor. We are doing some remodeling, so I will ask the guy who does the plumbing to look at this for me.

Randy R

[mcelhane]

The reason sinks have traps is to prevent sewer gas from getting into your house. If the trap runs dry, you will get that sewer smell. However, usually there is no trap on the vent pipe (shouldn't be one anyway). So, if the vent pipe isn't vented to the outside, you will get sewer gases inside. Extend the vent pipe at least to the attic space, but, better yet, to the outside.

[dnoyeB]

That is wrong. You want to probably put a "studor" vent on that. I had a plumber that left the vent off at my place as well. My wife kept getting sick too. Put a studor on that asap. Make the plumber do it. I know it can't pass code like that and I question te quality of a plumber that would leave it like that.

[Joseph Meehan]

We can only guess what the plumber did, but it sounds like he failed to put the breaker on it. You can't legally or properly vent to just an open pipe into a living space, it must be vented outside or one of the mechanical vents as I indicated above or dnoyeB indicated. You plumber either did an improper job or just failed to finish it.

[dnoyeB]

I'm no plumber, but it sounds scary to vent sewer gasses into the attic. You might not smell them, but there are other hazards of sewer gasses beyond the smell.

[PipeDown]

AKA. an Air Admittance Valve. They are allowed under one plumbing code but not the other (IRC, UPC) You need that or a direct vent outside or to the existing vent stack.

lookup AAV

The purpose of a vent is not to allow sever gasses to get outside (though they will occupy the pipe). The purpose is to prevent a vacuum from sucking the trap dry when water is drained on that branch or to prevent a pressure bubble at another fixture from erupting as a gieser.

[hallerb]

I'm no plumber, but it sounds scary to vent sewer gasses into the attic. You might not smell them, but there are other hazards of sewer gasses

beyond the smell.

-- Thank you,

YEAH! like a neighbor bozo dumps gasoline down his sewer, vapors might end up in your attic, sewer gas can contain methane, thats raw natural gas.

never vent into a interior space

[PipeDown]

Time to call the Mythbusters. For the mosrt part, methane vapors would be either too dense or not dense enough to ignite but there would be a sweet spot inbetween where it could be possible. The risks to sewer gas are mainly health and comfort. I can't remember even one sewer gas explosion making it to the news in my recent memory.

[Sacramento Dave]

The floor drain should be vented ( if that's what's there) the best fix if possible would be to tie the sink vent into the drain vent. The tie must be a minimum 6" above the flood rim of the sink ( were the water pours out of the sink onto the floor) It sounds like you had not quiet up to code job done. If a floor drain water evaporates out of the trap you no longer have a seal from sewer gas. There are fixes for this called Trap Primers but this might be beyond your plumbers skill level.

[George E. Cawthon]

Must be true otherwise they wouldn't show the sewers blowing up in all those movies. In some cases it was just the devil tho.