Hello,

I have been trying to figure out this weekend the best way to run the waste water pipes in my new house. The basement walls are poured, now I just have to do the plumbing before they can pour the floor.

I attached a picture of the layout of the basement, I would appreciate any help with:

1) Where should I run the waste water pipes under the floor to connect everything up?
2) I am really confused about vents, where should I run vents at (if any) from under the concrete floor?

Thanks for any help.

I do not want to assume anything since that layout is not labeled, is it your basement level? I see a 4" drain pipe exiting the building so I will assume your sewer is lower than your floor. I also see where the first floor drain comes down to the basement so I am a little surprised this design leaves out all the rough in which should include a drain for the future litchem.

Yes, this the basement.

Probably the reason the rough in for the kitchen is left out is because I designed it :) and I just threw that in at the last minute thinking about future use.

Should I also assume you will pull a permit? Call first since your building department may not even allow you to do this work, may require a licensed plumber for rough in.

Also ask if your code allow wet vents. Tom

It is already permitted, and I do not need a licensed plumber.

Yes, I can use a wet vent. Would a wet vent off the laundry and sink drains be enough or do I need a vent off the tub also?

Thanks

Hi kclaw...

Here is a basic layout for the underground. Give me a couple days and I will try to explode the view to include sizing and venting... O.K.?

Cleanouts will be needed in quite a few places... will explain later.

MARK

Mark:

That is exactly what I was looking for... Thanks a lot. I will lay it tomorrow.

I would love it if you could expand on the venting also if you get a chance.

Hi Kclaw:

OK... here's a blown up version of the underground drain system. The diagram includes the vents needed for the underground plumbing but it doesn't show how to connect all this together in the basement before taking the main vent from the basement upstairs. Confirm that you understand and ask any questions you need, too. I will post the specifics on connecting all the vents together in the basement after you finish/inspect this... O.K.?

All underground piping must be 2" minimum.

All elbows coming out of the ground must be long sweep elbows.

You must use WYE fittings to branch of the main drain... NO SANITARY TEES underground.

Dandy clean outs (or test tee fittings) must be installed at all fixtures as indicated below. This is especially important with the main drain going upstairs.

The 3"x2" wye at the toilet... picking up the sink and tub... that wye must roll above the center of the toilet drain line. At a minimum, it needs to roll slightly above the center line of the 3" toilet drain pipe. Here, use a 45 degree fitting to straighten out the angle of the rolled wye fitting so that the 2" pipe that picks up the tub and sink achieves a 1/4" pitch per foot of pipe. At a maximum, as in the bottom picture below, it can roll above the main drain off the top of the wye fitting IF the drain pipe won't be into the concrete at the high end of the drain at the sink. Use a long sweep 90 here if you can. That make sense??

4" pipe pitches at 1/8" per foot of pipe. 3" and 2" pipe pitches at 1/4" per foot.

Check to be sure that the floor drain doesn't need a vent. Most areas will not require a vent, but double check on this.

The washing machine will have a 2" Ptrap and a 30" piece of pipe for a standpipe.

Finally, the inspector will want you to test this system with water to a 10 foot head of pressure so we will need to discuss this, too... O.K.?

Let us know what you think...

MARK

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