It sounds like a lack of vents.
I would start with a vent on the washer.
I've had a problem since I have bought my house with my washing maching draining my bathtub and my toilet. I have snaked to and away from my house. I am currently on a community septic system that drains into an old mine shaft. Would like to know what may be causing the problem. Both the toilet and the bathtub drain fine unless washer has just emptied.
The washer has a new vent that was done when the previous owner remodled and built the laundry room. My main vent runs up through the roof. The washer's vent runs into the attic. The washer is only a few feet from the toilet and the bathtub. I know that the washer drains with a lot of force (more than the toilet and the bath tub), could this be the reason that my pipes may not be able to handle the force of the drain of the washer or am I going into left field?
You have a good point. A washer dumps mega amounts of water in a short time. That's why they require a 2" drain. There may be a size problem somewhere. Your washer standpipe should be 2" and after the trap go into at least a 3". I'd still check the vents as Terry suggested to make sure everything is located correctly, sized properly, and is not clogged.
You also could have a partially plugged drain downstream or a sewer that has a dip somewhere near the fixtures that you mentioned.
Hmmm... around here that's not allowed.Originally Posted by gyrine75
Vents have to go outside -- otherwise you'll end up with an attic full of (explosive) sewer gas...