OK, here it go's...I bought a 75yr old house and everything is in need of repair. Here is one of the things that has me stumped and I can not find a thread that explains it out for me.
The kitchen has a washing machine in it which was added sometime and a hole cut in the floor for the drain. The drain line runs down to the crawlspace and is a 1.5 inch black water line, not rigid and ties into the drain for the gray water field downstream from the kitchen sink line using a rigid Tee connection. These are the only 2 lines on this. The main line out of the house looks to be 4 inch PVC. The line from the washer to the Tee is about 20ft long and its also 15ft from the tee to the kitchen sink which looks like a 3in rigid line. There is no venting on this line for either the kitchen sink or the washer inside or outside the house or on the field. With the original washer when it ran air would bubble out of the kitchen sink. No water backup and the washer seemed to work fine just air and splashes. I surmised that the field was not large enough so first replaced the washer with a new HE machine that used less water. No dice. I then dug up by hand the gray field and replaced the single pipe there with 2 pipes on sand and gravel. I also put a surge barrel before the small field figuring with only a washer and a sink it would be big enough and would fix the problem but it still bubbled up into the sink. I then put a stodder vent on both the sink (under it) and behind the washer but it still backed up. I then removed the rigid connection where the washer went into the main line below the sink line and put a flexible tee there to see what would happen leaving the top open and water comes out of it where the washer comes into one side and the sink still bubbles but not quite as bad. Now what?
Anyone have a solution to this?
Is the field maybe still not large enough and I have to put a second surge barrel in or make the field itself bigger since the soil is only a few feet deep and then solid clay?
Vent down stream of both sink and washer maybe cutting into the main line outside the house and putting it there?
Change the washing machine line from 1.5in to 2 or 3in line?
Totally stumped here and all of the help I can get would be appreciated. Thanks