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VFR_Phil · Sep 16, 2013, 03:39 PM

I'm finishing out part of my basement and need advice on how to add a new sink.

My question is tied to the drain line for the sink. The basement already has a finished bathroom w/ shower, stool, and sink which drains into an ejector pit which pumps the wastewater up to the main drain line exiting the house to the septic tank.
Here is my question: How do I bring the wastewater into the pit? It's sealed and mounted flush to the concrete basement floor. Do I need to come in through the side (Under the floor) or can I punch a new hole in the lid of the pit? I'm assuming the latter but I'd like to know the dos and don'ts before I start. Or, do I need to add a whole new pit? The kid(s) at the home improvement store(s) couldn't help out much...

Any relevant info / advise would be much appreciated!

speedball1 · Sep 17, 2013, 08:43 AM

We need to get together on terms. Sinks are in the kitchen and lavatories are in bathrooms. What fixture are you planning to add? Let me know how you make out. Good luck, Tom

massplumber2008 · Sep 17, 2013, 04:01 PM

Hi Phil

Were is this "new sink" going to be added... is it anywhere close to the existing sink or tub drain?

Mark

VFR_Phil · Sep 18, 2013, 01:43 PM

Greetings Tom,

Thanks for the reply. It was going to be a lavatory I guess. To be clear, I'm looking to put in a "sink" for an art studio I'm making for my wife.

Disappointing news about busting up the floor though... I really wish I had had the builder add a stub out during construction 8 years ago, when it was easy...

I may just skip this part of the project altogether then. I wasn't counting on playing w/ concrete, and I don't want to create a future liability for home inspection etc if I go in through the lid and that's a no-no...

Thanks for the fast response!

Phil

massplumber2008 · Sep 18, 2013, 01:44 PM

Hi Phil

Perhaps you could answer my questions? I might actually have a couple ideas here... ;)

VFR_Phil · Sep 18, 2013, 01:53 PM

Mark,

Thanks for the reply.

The new sink would be in the basement on the opposite side of the ejector pit from the existing sink/shower stall. In other words, it is about 20 feet away from the existing bath with the ejector pit almost, but not quite in line and half way between them. However, there is a load bearing wall, a storage room, and a hallway in between. The pit is right next to the footing under the floor which supports the load bearing wall.

My question at this point is: Can I go into the pit through it's lid? Or, do I need to break up a concrete floor to make this fly. If I need to go through the concrete, I may not put the sink in... On the other hand, I don't want to go through the lid if that generates a future home inspection liability.

All the best to you Mark!

ma0641 · Sep 18, 2013, 02:12 PM

20 ft. creates 2 issues, slope and venting. The slope is a bit difficult to overcome unless there is some intermediate drain, the venting could be by an AAV if acceptable.

massplumber2008 · Sep 18, 2013, 02:21 PM

A few things come to mind...

First, you could purchase a simple LAUNDRY TRAY PUMP... has a small pump and basin that can fit under a vanity base. From there, the pump discharge pipe can be run over to any drain in the basement and hooked into that. This is 100% legal and keeps you from having to open up the floor.

Second idea would be to hook up a "temporary" sink and just cut a tee fitting into the sewage ejector pump VENT. It is not legal, but it would work perfectly. Heck, it may even be worth calling the local plumbing inspector and just ask him if this is even possible... kinda similar to "wet venting" a sink!

Third idea would be to cut into the cover of the basin, but you would need to have very specific size hole and gasket so that the hole could be made tight enough to keep sewer gasses from escaping the pit. Again, this may not exactly be legal, but I think it only takes a minute to call your local inspector and tell him an out of state plumber thought these suggestions were at least REASONABLE... ;) Zoeller (google) makes a gasket kit for the vent pipe that could probably be adapted for this.

Finally, do not forget that you need to vent the new sink. As ma0461 said, a mechanical vent (AAV) may be allowed in your area and if it is, they are great as long as they remain accessible (under sink is fine).

I'd call the local inspector and see what he thinks about these ideas... may actually approve of one, and if nothing else, you could certainly hook the new sink drain into the ejector vent TEMPORARILY!

Mark

VFR_Phil · Sep 18, 2013, 02:54 PM

Mark,

Thanks for the food for thought. You've definitely given me something to work with here...

A follow up question though regarding the laundry tray pump; Can I take the discharge from it up to the main waste line? I've not seen one before, so it may b e a silly question. I wasn't sure if the pump on that kind of unit would be rated for enough head to go up 8 feet and tye into the waste line. If so, problem solved and I can avoid the ejector pit altogether... (along with a check valve I'd assume)

The approach into the vent line is even better, fewer mechanicals, and I'll call the inspector to follow up. I've never had to contact "My local building inspector" so that in itself will be it's own adventure!

Lastly, I don't like this but I figure I'll ask now. I have a second pit, its open, for a basement perimeter drain tile. I'm assuming I CANNOT legally tie into that (It would be too easy! ) from a sink. Pretty sure the answer is no, just thought I'd check! :) Another question for said inspector?

Thanks Mark.

Originally Posted by massplumber2008

A few things come to mind...

First, you could purchase a simple LAUNDRY TRAY PUMP...has a small pump and basin that can fit under a vanity base. From there, the pump discharge pipe can be run over to any drain in the basement and hooked into that. This is 100% legal and keeps you from having to open up the floor.

Second idea would be to hook up a "temporary" sink and just cut a tee fitting into the sewage ejector pump VENT. It is not legal, but it would work perfectly. Heck, it may even be worth calling the local plumbing inspector and just ask him if this is even possible...kinda similar to "wet venting" a sink!

Third idea would be to cut into the cover of the basin, but you would need to have very specific size hole and gasket so that the hole could be made tight enough to keep sewer gasses from escaping the pit. Again, this may not exactly be legal, but I think it only takes a minute to call your local inspector and tell him an out of state plumber thought these suggestions were at least REASONABLE...;) Zoeller (google) makes a gasket kit for the vent pipe that could probably be adapted for this.

Finally, do not forget that you need to vent the new sink. As ma0461 said, a mechanical vent (AAV) may be allowed in your area and if it is, they are great as long as they remain accessible (under sink is fine).

I'd call the local inspector and see what he thinks about these ideas...may actually approve of one, and if nothing else, you could certainly hook the new sink drain into the ejector vent TEMPORARILY!!

Mark

massplumber2008 · Sep 18, 2013, 04:28 PM

Yes, you can take the laundry tray pump and connect it into the main drain line. The idea here is to pipe all up as high as you can at the pump and then let the waste flow via gravity (pitch the pipe) to the main drain. A check valve is a MUST here!

Yeah, you can't connect into the perimeter drain... don't even discuss that with the inspector... ;)

Let us know know you make out, OK?

Mark