all of our drains back up when we run the dishwasher or wash...

[antsy]

all of our drains back up when we run the dishwasher or washer down in our basement and we just snaked them all and come up empty

[antsy]

all of our drain back up down stairs when we run our dishwasher or washer and we just snaked them all and came up emty

[Deckman]

We had a similar problem. It turned out to be roots that were blocking the pipe, but a distance from the house. Some of our underground pipes are also sloping slightly upwards. Regularly snaking and root killer helps a lot.