At times my basement floor drain overflows. This does not happen all the time. For example, I can run the washer and the floor drain overflows. Run the washer again it does not. Same thing when flushing toilets and using the shower. It may not happen for weeks and then all of a sudden the floor drain overflows. The house is about 80 years old. I am told by a plumber that the line is clear via a camera and snake and that it is not being caused by anything from the house to the city sewer line. He says it is caused by backed pitched.Ok I really know absolutely nothing about plumbing and need some advice before spending $$$$$ to fix the problem. He wants to fix the problem by closing off the floor drain and running an elevated sewer line in the basement with a greater pitch. Does this make sense??? Thanks so much in advance for all replies and insights.

ask the plumber " if the pipe is back pitched causing an overflow, why does it clear itself and the re-occur?".

The symptoms you describe can very well be caused by a backpitched drain, however I would caution you to get another opinion, paying for a camera may just save you thousands. And watch the camera with the plumber if it is backpitched you will see significant standing water in the line. Consider also simply capping the problem floor drain with a removable plug.

If it's back-pitched it would never be clear, to verify with a camera. At the least, it would have fluid in it.

There are many benefits from his "cure". That is how we installed ALL our seweres when I was in the Chicago area, But, a stoppage due to backpitch would seldom cure itself so I owuld get a second opinion as to the real problem.