Kitchen sink old metal drain pipe leak help.

[cascade]

We own an old colonial brick house. Recently we discovered a leak coming from a kitchen sink/dishwasher metal drain pipe. Water was dripping in the basement from above where the drain pipe is coming down by the end joist. That drain runs about 2ft horizontally directly behind the sink cabinet and a corner cabinet. After calling a plumber he did not want to deal with getting to the wall behind cabinets and suggested bypassing old drain and put a new one thru the kitchen floor into the sink cabinet and fit it with an AVV. I did not like that idea at all. I ended up cutting an access hole in the back of the cabinet and the drywall right to the T fitting and the leaking area of the horizontal pipe. There is a rotted out hole in the bottom of the pipe that is about 2 inches long and about 3/4 wide. The hole starts about 2 inches from the T. Here are some options that I would like to ask about:

1. I was thinking about cutting the vent pipe above the T and replacing the entire run from the sink trap to where the pipe goes thru the end joist in the basement but not sure if the metal vent pipe going to the second floor and to the roof will have enough support. Looking at the picture there is another vent to the left about a foot away and these connect somewhere above but not sure how far and if the one pictured when resting on a new ABS T and ABS vertical pipe that with 2 45deg elbows rests on the foundation wall will have enough support.

2. I am considering removing just the rotted out pipe between the T and the trap. If i cut the horizontal pipe where the hole starts I could have about 1.5-2 inch of a stub to connect a new ABS pipe to. Would that be enough?

Picture attached.

Any suggestions?

 

[SHR]

Sawzall. Cut out all old pipe from sink including tee and all the exposed pipe in your picture. Replace with same size PVC and stainless steel shielded rubber couplings connecting to existing vent and drain pipes.

Very common, straightforward job. I do these all the time, at least one a week.

 

[phishfood]

Adding one consideration to the above, you need to make sure that the vent is supported in some way so that it does not fall down once you cut out the tee. I know that you said that it ties together with another vent somewhere up above, but you really don't want that falling down on you.

 

[cascade]

Thats what I was thinking. What do you think would work best? Steel clamp bolted to the wall? Could I use some of that stud as a support? I was also thinking about some sort of a flat steel bracket to basically grab the top vent, go around or under the new T and attach back to the bottom pipe like on the picture:

 

[ExtraMilePlumbing]

You can use a riser clamp , install it in the roof vent from the roof

 

[JoeWest]

If you're game to cut it ... then for sure I'd spray that crazy seal junk home depot sells that turns screen doors into sailboats. Waddia got to loose?

There's no pressure there so you may solve your problem in seconds and it might last years. If not ... hey, you're cutting anyway.

 

[cascade]

I already sealed it for now with an epoxy putty and it looks good.

Looking for options if it starts failing or other section rots out. I put in an access panel in the wall and a cover on the cabinets back wall so now i can monitor and have access to it.

The riser clamp is a great suggestion as long as this vent goes all the way to the attic but I am suspecting it to be a circuit vent connecting to the main one about a foot to the left somewhere above.

At least for now no leak and have time to figure it out.

Thank you all for help.

 

[frodo]

thats a good thing, if it offsets in the wall it will most likely not drop when you cut it

its them suckers that go straight up and out that are a pain.

what i have done in the past, it it goes straight up.

make the cut on top of the tee first...go on the roof pull the pipe up and remove

shove a piece of pvc down the hole. when your done, fold he lead over the edge of the pipe