3rd Floor Kitchen Sink Draining into 2nd Floor Sink. HELP!

ntl1991January 25, 2011

I have a plumbing problem...

My 3-family home has three vertically stacked kitchens. All three kitchens share the same drain line that vents through the roof. The 2nd floor called and told me that the kitchen sink was clogged. I went with my Liquid Plumber and plunger. After letting the gel sit for 15 minutes and plunging away, I didn't made any success. I went to the 3rd floor and turned on the hot water to see if the drain worked up there. It was draining fine.

I went back down to the 2nd floor, and the sink was full of hot water from the 3rd floor. I went back up to the 3rd floor and turned on the water again. Leaving it on, I went to the 2nd floor and checked the sink. I could see water flowing upwards from both of the drains, along with some black crud from the walls of the pipes.

The first floor (my kitchen sink) drains perfectly fine.

Here in RI, the temp has been below freezing for a few nights now; is it possible that I have a frozen drain pipe? I'm guessing the blockage (whatever it is) is somewhere below where the 2nd floor drain tee's in on the vertical stretch hidden in the wall (which happens to be an outside wall on the back of the house) that also extends through the roof as a vent at the very top.

Any ideas?



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You have a plug in the line below the second floor sink. The water is simply coming out of the lowest point in the system above the leak.
A snake should be run down the second floor sink drain line.

    Bookmark   January 25, 2011 at 7:51PM
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Thank for the reply. Before calling a plumber this morning, the 2nd floor called and told me that the standing water in her sink was now gone. I went up there and turned on the hot water on the 3rd and 2nd floor. Meanwhile, down in the basement, I could hear what sounded like chunks of ice hitting the elbow at the bottom of the waste riser.

Now that that's the drains are all fine, I think I have a related problem. This morning, after going into the basement while running the hot water, I could see a puddle of water under the riser pipe. There was dirt in the puddle and the dirt was in a path down the foundation wall. On top of the foundation wall, there was a bunch of wet dirt. (I'm pretty sure the dirt has always been there from the fire stop material and dust and whatnot.

Directly above the dirt on the top of the foundation is the hole in a 2x4 where the PVC riser runs up through the back exterior wall of the house, and then through the roof. The wood around the hole is wet with moisture, and some of the insulation I put in that hole around the pipe to stop a draft was moist too.

Is it possible that the PVC waste pipe had standing water in it from the blockage (whatever it was) and froze and cracked overnight? The temp last night dipped to 15 degrees Fahrenheit and stayed below 25 until 10:00 this morning. This riser pipe is in an uninsulated exterior wall on this 1940's house, and vents through the roof.

Any help would be appreciated.


    Bookmark   January 26, 2011 at 5:27PM
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Sounds like you have a major problem. I believe the pipe may have frozen and split. The water is leaking from the split.

    Bookmark   January 27, 2011 at 8:20AM
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