Connecting Utility Sink to Existing Vertical Drain Pipe

[zeetwoeight]

Hi all,

I want to install a utility sink in my basement by tying it into the existing 3" vertical drain pipe that comes from the second floor washroom. There is currently a clean-out located 13" up from the basement floor. My plan was to put in a 3"x3"x1.5" sanitary tee below the clean-out and orient it such that the 1.5" connection point on the tee would be facing outwards rather than to the side. I'd connect an elbow there and run the 1.5" branch line from the sink to the sanitary tee on the outside of the wall to avoid having to cut open the wall and cut studs. The sink will about 3' away from the current drain. So here are my questions:
1. should the tee be above or below the clean-out or does it matter?
2. is it ok to orient the tee the way described and run the 1.5" drain line from the sink on the outside of the wall?
3. any venting concerns? My house is 13 years old so I can only assume that this drain stack is tied into the primary vent stack at some point above.

I've done some plumbing in the past - installed and replaced sinks and toilets, moving hot water tanks, completed all PVC plumbing for an above ground swimming pool - so I'm not a complete newbie. I may very well engage a pro to do this for me but I'm curious at this point to know if this is a major piece of work for a DIY'er with some experience or if this should be a relatively straight forward job.

Appreciate any input on this.

Thanks everyone!

 

[Cacher_Chick]

If there are other fixtures connected to this drain line, you cannot use it as a combination drain and vent, a seperate dry vent must be intalled for the sink.


It would be best to tie in a new 2" drain on the existing stack, and then the work would be done if someone wanted to install a washer there later. The sink trap 1.5" is fine tied to its own 2" drain.

 

[Sponsor]

 

[zeetwoeight]

If there are other fixtures connected to this drain line, you cannot use it as a combination drain and vent, a seperate dry vent must be intalled for

It would be best to tie in a new 2" drain on the existing stack, and then the work would be done if someone wanted to install a washer there later. The sink trap 1.5" is fine tied to its own 2" drain.

Thanks. there are currently no other fixtures connected to this vertical drain in the basement. the drain comes from the second floor washroom. its highly unlikely a washer will ever go there as our home has our laundry room on the main floor. this utility sink is just being put in for a brew room (yes... I make beer and wine ). So will I still need what u describe?

 

[Asktom]

Yes, you need a dry vent before you connect to the 3".

 

[zeetwoeight]

Thank folks. I did some googling about this dry venting and put together this diagram. Is this what you are referring to or am I completely off track on this?

 

[Cacher_Chick]

No, if you are tying into an existing drain and vent stack, the new vent connection must be at least 42" above the floor of the highest fixture connected to the stack. Often it is less work to plumb a new vent through the roof or tie the new vent to the existing one up in the attic below where it goes through the roof.

 

[zeetwoeight]

No, if you are tying into an existing drain and vent stack, the new vent connection must be at least 42" above the floor of the highest fixture connected to the stack. Often it is less work to plumb a new vent through the roof or tie the new vent to the existing one up in the attic below where it goes through the roof.

Thanks. Since running a new vent up through the roof or connecting to the existing 42" above highest connected feature is not going to be do-able (from a financial and physical renovation perspective) is the use of an AAV appropriate in this case - assuming of course local building code allows this?

 

[zeetwoeight]

So I have confirmed with the my municipality planning dept that the use of an AAV is permitted as long as the AAV is accessible (which it will be). So would the following diagram be a proper way to install the AAV in the system to allow me to put in the sink? I read on another thread that the AAV can attached to a horizontal run as long as a WYE is used to connect a section of vertical pipe for the AAV install. Thanks.

 

[Terry]

So I have confirmed with the my municipality planning dept that the use of an AAV is permitted as long as the AAV is accessible (which it will be).

The last drawing works. The AAV works for that.

 

[zeetwoeight]

The last drawing works. The AAV works for that.

Thanks Terry. I have been reading a lot on this site about AAVs and I know they do not get the best reputation but the only other way for me to vent this sink would be a major reno of my first and second floors of a completed home to get a proper vent pipe to the roof or attic. Wife won't approve that so I can put in a sink to make beer

Will do some more research on this as well to find out if one brand is better than another.

 

[Terry]

I've been using Oatey and Studor.
There may be others. I don't use Cheater vents.