Why would kitchen sink water backing up in basement sink?

Answer 1

Probably a hair clog. Get a bucket and open the trap under the sink and clean it out. Chemical drain cleaner may also work but don't attempt to clean out the trap if you've used the chemical drain cleaner.

Answer 2

The most common reason for a sink line to plug is actually from soap build-up. Soaps are made from greases and fats and turn back into them when they sit in the line. They slowly make the pipe smaller and smaller until it plugs either from a chunk of food or any other debris going down. Potato peels, onions, pastas, and anything stringy like celery or banana peels can also plug the line.

Lavatory sinks, tubs and showers are usually plugged by a combination of soap build up and hair. Quite often lavatory sink back ups can be fixed by simply removing and cleaning the pop-up assembly.

Answer 3

All of the drain pipes in your house are connected to one pipe that either drains into the septic tank or the sewer system. It sounds like you have a clogged pipe somewhere down the line or a full septic tank. Try Drano or another liquid type drain cleaner. Follow the directions carefully as it is very caustic. If that does not work then you may have to call a plumber. If you have a drain snake you may be able to clear the clog yourself. Good luck.

Answer 4

Line to the sewer is blocked. Try filling the basement sink with hot soapy water and letting it go. That would clear grease out. Could have a root in your outside line.