Kitchen Sink Drain Line Collapsed

[Scottyculp68]

Hello,

Our home was built in '76, and we discovered the kitchen line running under the slab has collapsed. We bought and moved into it in 2020. Our insurance wants to reroute the pipe around the home into the septic tank. The old line is a 2-inch cast iron. Can I put a cap on the old line as we do not intend to break into the slab to replace it? We are starting to smell sewer gases coming from it through the kitchen sink drain. Thank you.

 

[WorthFlorida]

If you're smelling it from the sink drain, that means gas is pushing back past the trap, or the trap is being sucked dry allowing odors to enter the home. If proper venting of the trap, it should not happen. Do you know if there is a roof vent on the kitchen side of the home? It should be checked that it is not plugged up with a birds nest or a dead varmint, however, poor venting usually means slow drainage and gurgling. Has the septic tank been checked and has it been pumped out recently?

There will alway be crud in the pipe and odor will creep along the outer part of the pipe and the soil or concrete. To totally block it off would be to fill the pipe with cement or foam from one end to the other. I'm assuming the new pipe will be run out the wall and then trenched along the home to the septic tank.

What is not known from your post is the the kitchen drain 2" pipe. Is it wye'd into a three inch main (under the concrete) that also takes drain water from the bathrooms, etc.? If it does and most likely, plugging the pipe with cement may not be possible. Capping it off at the sink only, drain water could still work back from a back up or the pipe is not sloped enough to drain completely so waste water still lays in the section of a collapsed pipe. It may have collapsed because of a poor slope and standing water in the pipe and it rusted it away.

If it is known where the wye is to the 3" main, maybe just that section of floor can be cut out to cap off the pipe at the wye and the old pipe can be drained out and filled with cement.

 

[Sponsor]

 

[Jeff H Young]

I would want my crushed section of piping to not be connected to the live drainage system. dig it up place cap on a sound section of pipe . if you don't want to make hole in floor that's your preference but I'd want it right

 

[Scottyculp68]

Thank you all for the information. I have a lot to consider and will look further into it.