I live in a townhome built in the 70s and with this many families living in close quarters for all these years, the drains are showing their age and occasionally back up. It's only happened to me once in the year I've lived here but my neighbor says hers does it fairly often, especially when she does a lot of laundry in one day. Her solution was a "catch barrel". From what I understand, the basic premise is that the washer drains in to a large plastic barrel, similar to a rain barrel, and then from there in to the drain. This allows the washer to pump, with it's normal force, in to the barrel and then the drain to take the water in at a slower pace with the barrel acting as a way to slow the drain water down, thus preventing too much entering the drainage system at one time and backing up.
It makes sense but I am not sure the logistics. Would the barrel need to be raised up off the ground? I presume the washer hose would drain in to the top and then an outlet hose would run from the bottom in to the drain? Would it go in to the washer drain pipe or in to the floor drain? Would I need to use a small outlet tube to slow down the water? How small?
I'd like to have the info and begin collecting materials as I come across them at Habitat or freecycle.