My house was built in 1998 in Minnesota by Oren-Thompson. My kitchen drain flows into the main house drain line after the basement floor drain but before the main soil stack (thankfully). From the street, it would go MSS, then kitchen drain, then the end is the basement floor drain, if that makes sense. Whenever water is put down the kitchen drain, the basement floor drain backs up with water and food particles all over the basement. I've run an auger down both the kitchen and floor drain lines as far as it would go (50-60'?) and it loosened it up and let everything drain, but a few days later it was blocked again . I've tried Liquid Plumber (twice), pouring 2 gallons of boiling water down the drain, and even a baking soda-followed-by-vinegar treatment others had suggested. Nothing is working. I'm assuming there's sludge in the line, not a hard clog, that keeps stopping things up. What can I do about it?