Hi all,
I have a house that is more than 100 years old. Our washing machine is in the basement. About 30 feet over, we have a half bath. Whenever we run a large load, water drains out of the washing machine OK, but backs up into the bathroom sink, and eventually over the counter and onto the floor.
Some other info (and please let me know what else you need):
The drain hose comes up from the washing machine into a PVC pipe. No water comes out from that. Next to where the hose goes into the PVC is another opening in the PVC at the same height. (Think of a "U" where the hose goes into one part of the U and the other end is open)
Is this a clog problem? If so, is there any chemical I can use to solve it? (we have some PVC, some cast iron, and some copper) Or is this a venting problem? Should the open end of that "U" be higher than the side where the drain hose goes in?
I don't know a lot about plumbing, but I know I can't afford a plumber! Any help would be greatly appreciated!
Thanks!

City sewer or a septic tank? I can see no problems with the "U" on the stand pipe. I would suggest that you rent a sewer snake and run it down the lavatory vent in your bathroom. Put out enough cable to reach the base and 20 foot more. Good luck, Tom

It's city sewer. I just got an auger from a neighbor, so I'll give it a go.
Thanks again