I just put in a new drain stack. Viewing straight down the horizontal portion of my sewer main from the main stack cleanout, with my flashlight I see a bit standing liquid in the pipe. Its a bit on the bottom surface of the pipe maybe 1/8" deep in a few random spots. There are no standing solids in the pipe...(I had just flushed down some solid for this testing).

Is it normal to see some water in a drain pipe like that? Or is that a slight belly?

or perhaps a better way to ask .... should the drain pipe be completely removed of moisture at all time?



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is the horizontal that you refer to new or existing?

Ideally, it should not have any water in it, but what you describe should not create any problems.

Its new. I think I adequately supported the pipe during backfill.

What I observed was directly after running water. The amount of water is a skim along the bottom of the pipe (less than 1/8" deep)... I would describe what I saw at that moment as a small puddle.

The only reason it concerned me is that its close to where I made the transition.



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i agree with my friend from AZ..

I recently visited a friends condo that he recently purchased at the beach. It has a huge partially underground (approx 7 feet below grade) garage. I noticed that the drain piping was almost flat for about 40 feet. It appeared to have about 1" of fall over that length. There were a number of these flat areas for different drops as the Unit has approximately 200 condos. I commented that normally the code requires 1/4" per foot fall and that it should have 10" of fall from the fartest drop to where it enters the Verticle mainline on each section. But I then thought that the inspector may have overlooked this installation due to the 4 storys of drop that would cause a flushing of the flatter area. It aparently is working OK as he states that there is no mention of abnormalplumbing drain problems in the Disclosure Statement that was required to be signed off in Escrow prior to the Close. Do you guys see any problems with what I have described? This system is Cast Iron No Hub and there are numerous No-Hub caps on the end of the runs on combinations.

Thanks for the replies.

What about a freeze concern?

Can I assume since the portion of old pipe I replaced never froze that this one wouldn't either?



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A drain line can ONLY freeze if it has water in it.

Interesting question srloren. Maybe cut and paste your question in a new thread so it will get a response.

I think what I saw was residual water still moving thru the system, like dripping off the interior walls or something...

For example, I can run water in a tub or sink and it flows excellent. When you turn off the fixture a few minutes later I can see a small stream, perhaps still moving slowly. This is looking down from my outside cleanout. That stream at that point is the thickness of my index finger.

How about in the case of corroded steel sewer pipe, where there rust and sludge and crap in the bottom flow path of the pipe... doesnt that stuff hold pockets of water that would freeze?



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