I have a small rental house that has a plugged up kitchen sink drain. The kitchen sink drain pipe in the basement is also leaking. I have no way of repairing the leak ( can't get a wrench in there) much less getting a snake through all the 90 degree bends. It looks like the plumbing in this house was installed incorrectly 80 years ago.

The drain pipe goes down through the floor with no vent pipe. It takes a 90 degree turn through the wall to the outside, where it takes another 90 degree turn down into the front walkway. About a foot of it is exposed. I have no idea where it goes after that. It is a steel pipe, not cast iron. The main drain line is on the far opposite end of the basement and it does not join it, at least not inside the basement. Maybe it does under ground.

Here is my plan: To install a new kitchen drain pipe on the inside of the basement along the wall all the way to the utility sink line and join it with a Y coupler. The pipe would go about 40 feet along one wall and about 25 feet along another wall and then 8 more feet along the back wall. How much drop per foot do I need for this pipe and is this an acceptable way to do it? Should I use 2" pipe?

 

That's way too much pipe to install, IMO, not to mention that they won't be able to use both sinks at the same time.

If you post some pics to photobucket.com , we may be able to find a better way.

 

I can't make the pipe shorter and I can't move the sink or the main drain line stack at the far end of the basement. Why can't I use 2 sinks at the same time?

 

By code you can't use a 90 degree fitting to make the urn you need to use a tee-wye combo fitting Also use a female adapter on the end and a cap for cleaning. Is there some way you can get a more direct route for the pipe? Can you go straight across the basement and then hook into the main stack with a saddle?

 

The drain won't be able to handle that much water at the same time.

I second mgmine's question. Can't you run to the main drain some where?

 

The basement already has only 7' between the floor and the upper joist. I can't run it diagonally because the pipe would be so low that I would hit my head on it. Would I have to go to a 3" pipe to handle the sink drain?

 

You sure? What if you sawzalled out a section, including the leak, and then while it was open, snake from both directions, and also maybe use one of those rubber devices you screw on the end of a garden hose, that expands in the pipe, and blast it downstream. Then close it back up using a piece of pvc and Fernco fittings on each end.

Yes, this is a cobble. But short of there springing more leaks in that drain pipe in the near future, it could last who knows how long. Plus you'd have a way to clean it out in the future. You obviously could get fancier than this by incorporating a cleanout wye in that piece of pvc.

Oh, and if nothing else, by sectioning out some of that metal pipe, you will find out how bad the inside of that pipe is, as that also might make any decision you make easier then.

 

That sounds like a good idea. I will saw the outside section off the top right at the 90 degree bend and try cleaning it out and checking the inside. I will let you know what it looks like and if I get it clear.

 

There is this condo-type apt I have to maintain. The goofy thing with this place is they ran the pvc drain across half the basement ceiling, then near the outer walll it takes a 90 and again goes halfway across the basement ceiling. It has the minimal drop per foot. In order for me to clean all the greasy goo out of that pipe, I HAD to cut open that pipe, about 1/4 to midway, so I could clean it from both directions. I had to be up on a ladder since the pipe was between joists for 1/2 the run. What a job clearing that gook out of there. What happens is that even if you just snake it, without the suggested water blasting it out after, is when you pull the snake back out, the gook can refill back in where the snake had corkscrewed through it. I then Fercoed it back together. Only to have to go back there about 1 -2 years later and do it all over again. But at least that time I knew what I was in for, and it went faster, due to my easy-to-gain access point.

Oh -make sure you support one or both cut ends of the steel pipe near the pvc piece, if necessary!

 

The steel pipe goes down into the cement front walkway, so it is already supported. I've never seen a drain pipe go outside through the wall 12 inches above the ground. I don't know where the other end is either.

 

Maybe it goes straight down into the 4 inch sewer line out there - IF you are on city. If on septic, maybe it goes to a grease trap, and/or just into pipe on way to the septic. You live in the deep south somewhere?

 

I'm on septic and the tank is in the backyard. I can see the main large cast iron stack coming out of the ground at the opposite end of the basement. If it joins that, it still is going a long distance.

 

Ok, today I got the old drain pipe cut out all the way from the sink to the outside pipe. The sawzall worked perfect. I never would have got a pipe wrench in there. So now I just have a 2" pipe sticking up out of the front walkway. I can see down the pipe and it takes a 90 degree bend to the right. I tried to get my snake past the bend but it wouldn't go. Should I get a fitting to put on the end of my hose to seal to the pipe and try to blast the clog free? Should I use hot water? The pipe didn't look too bad inside from what I could see.

 

I installed a new drain pipe from under the sink and to the outside pipe with a clean out plug. I added a stador valve under the sink also since there was no vent. I put it all together and it still has the same problem. It backs up after a couple minutes of running water and starts to bubble. I went outside and opened the clean out plug and a big rush of air came out and them it drained real fast. It works as long as the clean out plug is out so the air can escape. Why is it doing this?

 

Good question! It sounds like a venting problem. Can you install a vent cap where the plug was, if so then it sounds like it work.

 

If you can't install a vent in that spot, pro-vent should work anywhere in the line. Of course, outside is preferable.

 

You are compressing the air inside the pipe. A vent's purpose actually is not to alieviate compressing air. It is to actually introDUCE fresh air into the pipe. The water when going down the drain or sewer pipe, will try to pull a vacuum on the air in the pipe upstream(if there is no vent), and can actually pull water out of a trap. But by having a vent, that lets air in(not out) to equalize the pressure, and stop the vacuum. Once the water is passed, yes, sewer gases can positively discharge out the sewer pipe then, due to the lower atmospheric pressure up by the roof.

Are you sure that if you leave that clean out plug out, that the kitchen sink really will drain indefinitely? Have you tried to leave out the cleanout plug, then fill both sink basins and pull the plug, and continue to run the sink water, and run outside and watch and see if not just air gushes out that pipe, but water also? You may want to have a helper so you can be outside when the stoppers are pulled on the sink basins and also your helper can make sure water does not overflow the sink, just in case.

I'm suspicious of a blockage downstream from the cleanout.

 

You are right. I left open the clean out plug and it still backs up, only when I fill the sink, then open it so that it has maximum water flow. Can I use a drain cleaner to open it up? What is safe for a septic tank?