Venting for utility sink

[user10]

I want to install a utility sink in the garage. I opened the wall in the garage and found a waste pipe, from a bathroom upstairs. Can I tap into this waste pipe for my utility sink?

 

[RioHyde]

You can tie into that drain, but you're going to need to vent the utility sink or everytime someone flushes, the sinks trap is going to loose its seal.

 

[Sponsor]

 

[user10]

what wpuld happen if the waste pipe is used as a vent

whta would happen if the waste pipe from the upstairs bathroom was used as the waste and vent for the utility sink?

 

[RioHyde]

Everytime someone flushed the toilet the utility sink trap would be siphoned and you'd get a sewer gas smell coming out of the u/s drain

 

[user10]

How effective are trap air vents?

Are trap air vents reliable and offer good performance?

 

[Gary Swart]

If you are refering to air admittance valves, many plumber on this board have no use for them. I have 2 in my home and they work fine. You do have to have an outside vent in the system, and I would not bury a AAV in a wall or other difficult to access place.

 

[RioHyde]

AAVs are allowed by code here in Ohio as long as there is a vent on the system. I try not to install them however because actually venting the fixture works better. In some cases though they may be a necessary evil. As Gary said, dont bury it in a wall or put it in an inaccessible location. You'll want to be able to get to it so it can be changed when it fails.

Good luck

 

[user10]

What is venting the fixture?

Thank you in advance.

 

[EAP]

AAVs are allowed by code here in Ohio as long as there is a vent on the system. I try not to install them however because actually venting the fixture works better. In some cases though they may be a necessary evil. As Gary said, dont bury it in a wall or put it in an inaccessible location. You'll want to be able to get to it so it can be changed when it fails.

They must be code approved in your area to use. They must be placed at least 4 inches above the top of your trap but you must attach it to a seaparate fitting before the trap to accomplish that. And yes they must be accessible in case of failure, meaning you can't hide them in walls.

Yeah, a number of plumbers don't like them, but I don't think I would call them a necessary evil.

I may be opening a firestorm by saying this, but they serve a worthwhile purpose in many installations understanding their limitations such as these are no substitute for at least one traditional vent-to-roof to allow sewer gas to be released, something the AAV will not permit. In many cases, they perform as well as a traditional vent. These have been in use in Europe for example since 1972 and here in the U.S. since 1989 in some areas. Some of the manufacturers of these devices (well known plumbing suppliers) offer a lifetime guarantee.

Their use as a substitute in a complicated and labor-intensive island venting scheme are notable and impressive.