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Trying to install basement sink

Posted by bigyellow (My Page) on
Tue, Dec 2, 08 at 6:50

Hey, guys. I'm trying to install a basement sink, but the waste pipe is about four feet off of the ground. Looking at the article here

I can solve the problem by hooking up the sink as normal, but have it drain to a sump box/pump combo. I'm a little confused, however. There are two drains out of the box, one for the actual water and one going to the "vent stack", as the article mentions. Why do I need the second pipe coming out of the box? Shouldn't all of the exhaust gases leave the box through the drain coming out of the box on the left? Is it because there's a check valve on the left to make sure water doesn't flow back into the box?

If my assumptions are right, is the waste stack and waste pipe the same thing? If so, I would cut into my pvc waste pipe and have the pipe on the right (coming out of the sump box) go to it. I was then planning on having the pipe on the left drain into the existing drain for the washing machine.

Does this sound correct? Any help would be greatly appreciated.

Follow-Up Postings:

RE: Trying to install basement sink

A vent pipe is required because the box is sealed and air must be displaced as it fills. Likewise when pump starts, air must be able to make it back into sealed sump, otherwise it will airlock.

Other than that, proper venting is code everywhere and needed to vent the nasty odors that can accummilate.

RE: Trying to install basement sink

This is a sewage ejector which would require a separate vent up thru the roof (Pipe on right). You may want to call your local plumbing inspector and ask if a studor vent is acceptable. If you install this, make sure to buy lint traps to reduce the maintenance on the pump.

Take Care,

Dan Martyn

RE: Trying to install basement sink

Hey, thanks a lot, guys. Okay, the following image

Shows the waste pipe for the entire house (1) and the outlet for the washing machine (2). Can I just expel the water to (2) and cut into (1) and vent the fumes there, considering that (2) should (I believe) have a clear path to the vent stack?

RE: Trying to install basement sink

Studor vents won't work on ejectors & sealed laundry sumps

It will let air in during pump down cycle but stay sealed during fill from sink draining, not letting air back into receptor causing an air lock, backed up drain and possible flooding.

I learned that quick as a young new homeowner adding a bath in basement.

RE: Trying to install basement sink

Thanks for the help, guys. First off, I really didn't understand what I was getting into before starting this project. There's no way you can vent into the waste pipe for many reasons! z1700, in the end, I actually did land up using a studor vent. So far, it seems to be working like a charm. I ran the idea by a number of plumbers, including the town plumber. It's legal to use them where I live (westchester, NY) and I'm amazed at just how quickly the sump gets rid of the water. As the pics I've attached show, my only issue now is that I have to run a line for a new circuit. Considering the pump uses 8.5 amps, I don't think I can get away with running this on an existing circuit. My box is a little full, so I may have to either go with half circuits or get someone to run 200 amp service to the house (I have 150 amps right now). But that's another issue for another forum! Once again, thanks.

Btw, it was the first time I ever worked with PVC (I've soldered many copper pipes before) and really tried to be neat with the purple primer. As you can see from the photos, I didn't succeed!




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