This has only happened once so far but wanted to know if it will get worse. The upstairs toilet was flushed and about a 6" puddle of raw sewage came out of the floor drain in the basement. I poured hot water down the floor drain and tried flushing the upstairs toilet several more times and no sewage backed up out of the floor drain. Will this happen again? Is the main drain plugging up. I don't know where to start to look?

Sound like the main drain is getting clogged. Are you on a sewer line to city or on site septic?

Also do you put grease down the kitchen sink when done cooking?

The reason I ask is hot water to clear a line usually indicates Grease build up. Normally hot water does little to clear a line.

Get back for to us so help shed more light.

Yes we are on a city sewer and yes she does pour grease down the kitchen sink and runs the hot water for about 5 min. After reading some other posts I have noticed the floor drain that I mentioned seemed to have soapy water around it when using the washing machine. I thought that the washing machine was leaking but maybe it is the floor drain backing up.

Sounds like a grease problem as I mentioned before.

I would heat up 5 gals or more water and send the grease down the line. Also there are treatments for grease in sewer lines. I would use the hot water method first.