My mom says her washing machine drain overflows every time she washes a load of clothes. It is flooding her bathroom. She says that the problem seems to get better if she washes more than one load of clothes at a time. A friend has tried to snake the drain, but this hasn't resolved the problem. She seems to think that her septic may need to be pumped, but she isn't experiencing any problems with backups in the toilet, bathtub or sinks... only slow drainage. Any suggestions?

A power auger may work better. Skin, oil and lint are like cement in the drain.